ETH Price: $2,068.95 (-2.40%)

Transaction Decoder

Block:
16211521 at Dec-18-2022 12:17:11 PM +UTC
Transaction Fee:
0.002986222325077875 ETH $6.18
Gas Used:
221,745 Gas / 13.466920675 Gwei

Emitted Events:

311 QuadraticFundingVotingStrategyImplementation.Voted( token=0x00000000...000000000, amount=110000000000000, voter=[Sender] 0x1b48571aae5cc8a7bf54a92f8f8d7d016b602dab, grantAddress=0x06fd1a0356a1e58852721331a3aed1b7ebe214ed, roundAddress=[Receiver] RoundImplementation )
312 QuadraticFundingVotingStrategyImplementation.Voted( token=0x00000000...000000000, amount=110000000000000, voter=[Sender] 0x1b48571aae5cc8a7bf54a92f8f8d7d016b602dab, grantAddress=0x6078c8eeb7ed8916a8f1e85dc8f6e780c09a89ff, roundAddress=[Receiver] RoundImplementation )
313 QuadraticFundingVotingStrategyImplementation.Voted( token=0x00000000...000000000, amount=110000000000000, voter=[Sender] 0x1b48571aae5cc8a7bf54a92f8f8d7d016b602dab, grantAddress=0x39d77e51c485f1ff65b1b3b42e9f67cda221f597, roundAddress=[Receiver] RoundImplementation )
314 QuadraticFundingVotingStrategyImplementation.Voted( token=0x00000000...000000000, amount=110000000000000, voter=[Sender] 0x1b48571aae5cc8a7bf54a92f8f8d7d016b602dab, grantAddress=0x95d34596db5a2f65f2a92b97955bf7920fd1c9e3, roundAddress=[Receiver] RoundImplementation )
315 GnosisSafeProxy.0x3d0ce9bfc3ed7d6862dbb28b2dea94561fe714a1b4d019aa8af39730d1ad7c3d( 0x3d0ce9bfc3ed7d6862dbb28b2dea94561fe714a1b4d019aa8af39730d1ad7c3d, 0x000000000000000000000000a9a5d3169734bb191a696049b92c15b207888c58, 0000000000000000000000000000000000000000000000000000640b5eece000 )
316 QuadraticFundingVotingStrategyImplementation.Voted( token=0x00000000...000000000, amount=110000000000000, voter=[Sender] 0x1b48571aae5cc8a7bf54a92f8f8d7d016b602dab, grantAddress=GnosisSafeProxy, roundAddress=[Receiver] RoundImplementation )
317 QuadraticFundingVotingStrategyImplementation.Voted( token=0x00000000...000000000, amount=110000000000000, voter=[Sender] 0x1b48571aae5cc8a7bf54a92f8f8d7d016b602dab, grantAddress=0xd27e1a1a60ebc1b70f4cae5265092c0f6edc7f9d, roundAddress=[Receiver] RoundImplementation )
318 QuadraticFundingVotingStrategyImplementation.Voted( token=0x00000000...000000000, amount=110000000000000, voter=[Sender] 0x1b48571aae5cc8a7bf54a92f8f8d7d016b602dab, grantAddress=0x81c776d0d7f7d9d3699851993ecaa88a46187f11, roundAddress=[Receiver] RoundImplementation )
319 GnosisSafeProxy.0x3d0ce9bfc3ed7d6862dbb28b2dea94561fe714a1b4d019aa8af39730d1ad7c3d( 0x3d0ce9bfc3ed7d6862dbb28b2dea94561fe714a1b4d019aa8af39730d1ad7c3d, 0x000000000000000000000000a9a5d3169734bb191a696049b92c15b207888c58, 0000000000000000000000000000000000000000000000000000640b5eece000 )
320 QuadraticFundingVotingStrategyImplementation.Voted( token=0x00000000...000000000, amount=110000000000000, voter=[Sender] 0x1b48571aae5cc8a7bf54a92f8f8d7d016b602dab, grantAddress=GnosisSafeProxy, roundAddress=[Receiver] RoundImplementation )
321 QuadraticFundingVotingStrategyImplementation.Voted( token=0x00000000...000000000, amount=110000000000000, voter=[Sender] 0x1b48571aae5cc8a7bf54a92f8f8d7d016b602dab, grantAddress=0x8ddfa84bbf59c0e6dbd05a56e9b9931b64255f08, roundAddress=[Receiver] RoundImplementation )
322 QuadraticFundingVotingStrategyImplementation.Voted( token=0x00000000...000000000, amount=110000000000000, voter=[Sender] 0x1b48571aae5cc8a7bf54a92f8f8d7d016b602dab, grantAddress=0x2906e0181f371b7a4c4bffe13e31b2a917b368e8, roundAddress=[Receiver] RoundImplementation )

Account State Difference:

  Address   Before After State Difference Code
0x06Fd1a03...7ebE214ed 4.687808845524965493 Eth4.687918845524965493 Eth0.00011
0x0e5C6c79...BD555eEbe 2.4915899548588087 Eth2.4916999548588087 Eth0.00011
0x1B48571A...16B602DAb
0.009218198433174 Eth
Nonce: 17
0.005131976108096125 Eth
Nonce: 18
0.004086222325077875
0x2906e018...917B368E8 2.100230676124889028 Eth2.100340676124889028 Eth0.00011
0x39D77e51...dA221F597 2.539339369326555416 Eth2.539449369326555416 Eth0.00011
0x6078c8ee...0C09a89fF 2.304471278155633728 Eth2.304581278155633728 Eth0.00011
0x7a2B50ff...DbbC0A9bA 3.27834906198515 Eth3.27845906198515 Eth0.00011
0x81c776d0...A46187F11 2.804334587343195391 Eth2.804444587343195391 Eth0.00011
0x8dDfA84b...b64255f08 3.318001625437943053 Eth3.318111625437943053 Eth0.00011
0x95d34596...20Fd1c9e3 0.494000112381842276 Eth0.494110112381842276 Eth0.00011
0xd27E1a1a...f6eDc7F9d 2.711859093740303094 Eth2.711969093740303094 Eth0.00011
(stakefish: Fee Recipient)
962.43097914227815898 Eth962.431083231514567625 Eth0.000104089236408645

Execution Trace

ETH 0.0011 RoundImplementation.vote( encodedVotes=[AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAAb9GgNWoeWIUnITMaOu0bfr4hTt, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAGB4yO637YkWqPHoXcj254DAmon/, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAADnXflHEhfH/ZbGztC6fZ82iIfWX, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAJXTRZbbWi9l8qkrl5Vb95IP0cnj, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAA5cbHn0ShnZjdWNTCLTovvVVe6+, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAANJ+Ghpg68G3D0yuUmUJLA9u3H+d, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAIHHdtDX99nTaZhRmT7KqIpGGH8R, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAHorUP861A4zWpSmhYq3J/27wKm6, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAI3fqEu/WcDm29BaVum5kxtkJV8I, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAACkG4BgfNxt6TEv/4T4xsqkXs2jo] )
  • ETH 0.0011 RoundImplementation.vote( encodedVotes=[AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAAb9GgNWoeWIUnITMaOu0bfr4hTt, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAGB4yO637YkWqPHoXcj254DAmon/, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAADnXflHEhfH/ZbGztC6fZ82iIfWX, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAJXTRZbbWi9l8qkrl5Vb95IP0cnj, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAA5cbHn0ShnZjdWNTCLTovvVVe6+, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAANJ+Ghpg68G3D0yuUmUJLA9u3H+d, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAIHHdtDX99nTaZhRmT7KqIpGGH8R, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAHorUP861A4zWpSmhYq3J/27wKm6, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAI3fqEu/WcDm29BaVum5kxtkJV8I, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAACkG4BgfNxt6TEv/4T4xsqkXs2jo] )
    • ETH 0.0011 QuadraticFundingVotingStrategyImplementation.vote( encodedVotes=[AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAAb9GgNWoeWIUnITMaOu0bfr4hTt, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAGB4yO637YkWqPHoXcj254DAmon/, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAADnXflHEhfH/ZbGztC6fZ82iIfWX, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAJXTRZbbWi9l8qkrl5Vb95IP0cnj, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAA5cbHn0ShnZjdWNTCLTovvVVe6+, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAANJ+Ghpg68G3D0yuUmUJLA9u3H+d, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAIHHdtDX99nTaZhRmT7KqIpGGH8R, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAHorUP861A4zWpSmhYq3J/27wKm6, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAI3fqEu/WcDm29BaVum5kxtkJV8I, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAACkG4BgfNxt6TEv/4T4xsqkXs2jo], voterAddress=0x1B48571Aae5Cc8A7BF54a92F8f8D7d016B602DAb )
      • ETH 0.0011 QuadraticFundingVotingStrategyImplementation.vote( encodedVotes=[AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAAb9GgNWoeWIUnITMaOu0bfr4hTt, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAGB4yO637YkWqPHoXcj254DAmon/, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAADnXflHEhfH/ZbGztC6fZ82iIfWX, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAJXTRZbbWi9l8qkrl5Vb95IP0cnj, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAA5cbHn0ShnZjdWNTCLTovvVVe6+, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAANJ+Ghpg68G3D0yuUmUJLA9u3H+d, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAIHHdtDX99nTaZhRmT7KqIpGGH8R, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAHorUP861A4zWpSmhYq3J/27wKm6, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAAI3fqEu/WcDm29BaVum5kxtkJV8I, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAGQLXuzgAAAAAAAAAAAAAAAAACkG4BgfNxt6TEv/4T4xsqkXs2jo], voterAddress=0x1B48571Aae5Cc8A7BF54a92F8f8D7d016B602DAb )
        • ETH 0.00011 0x06fd1a0356a1e58852721331a3aed1b7ebe214ed.CALL( )
        • ETH 0.00011 0x6078c8eeb7ed8916a8f1e85dc8f6e780c09a89ff.CALL( )
        • ETH 0.00011 0x39d77e51c485f1ff65b1b3b42e9f67cda221f597.CALL( )
        • ETH 0.00011 0x95d34596db5a2f65f2a92b97955bf7920fd1c9e3.CALL( )
        • ETH 0.00011 GnosisSafeProxy.CALL( )
          • ETH 0.00011 GnosisSafe.DELEGATECALL( )
          • ETH 0.00011 0xd27e1a1a60ebc1b70f4cae5265092c0f6edc7f9d.CALL( )
          • ETH 0.00011 0x81c776d0d7f7d9d3699851993ecaa88a46187f11.CALL( )
          • ETH 0.00011 GnosisSafeProxy.CALL( )
            • ETH 0.00011 GnosisSafe.DELEGATECALL( )
            • ETH 0.00011 0x8ddfa84bbf59c0e6dbd05a56e9b9931b64255f08.CALL( )
            • ETH 0.00011 0x2906e0181f371b7a4c4bffe13e31b2a917b368e8.CALL( )
              File 1 of 7: RoundImplementation
              // SPDX-License-Identifier: AGPL-3.0-only
              pragma solidity 0.8.17;
              import "@openzeppelin/contracts/access/AccessControlEnumerable.sol";
              import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
              import "@openzeppelin/contracts/utils/Address.sol";
              import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
              import "../votingStrategy/IVotingStrategy.sol";
              import "../payoutStrategy/IPayoutStrategy.sol";
              import "../utils/MetaPtr.sol";
              /**
               * @notice Contract deployed per Round which would managed by
               * a group of ROUND_OPERATOR via the RoundFactory
               *
               */
              contract RoundImplementation is AccessControlEnumerable, Initializable {
                // --- Libraries ---
                using Address for address;
                using SafeERC20 for IERC20;
                // --- Roles ---
                /// @notice round operator role
                bytes32 public constant ROUND_OPERATOR_ROLE = keccak256("ROUND_OPERATOR");
                // --- Events ---
                /// @notice Emitted when the round metaPtr is updated
                event RoundMetaPtrUpdated(MetaPtr oldMetaPtr, MetaPtr newMetaPtr);
                /// @notice Emitted when the application form metaPtr is updated
                event ApplicationMetaPtrUpdated(MetaPtr oldMetaPtr, MetaPtr newMetaPtr);
                /// @notice Emitted when application start time is updated
                event ApplicationsStartTimeUpdated(uint256 oldTime, uint256 newTime);
                /// @notice Emitted when application end time is updated
                event ApplicationsEndTimeUpdated(uint256 oldTime, uint256 newTime);
                /// @notice Emitted when a round start time is updated
                event RoundStartTimeUpdated(uint256 oldTime, uint256 newTime);
                /// @notice Emitted when a round end time is updated
                event RoundEndTimeUpdated(uint256 oldTime, uint256 newTime);
                /// @notice Emitted when projects metaPtr is updated
                event ProjectsMetaPtrUpdated(MetaPtr oldMetaPtr, MetaPtr newMetaPtr);
                /// @notice Emitted when a project has applied to the round
                event NewProjectApplication(bytes32 indexed project, MetaPtr applicationMetaPtr);
                // --- Modifier ---
                /// @notice modifier to check if round has not ended.
                modifier roundHasNotEnded() {
                  // slither-disable-next-line timestamp
                  require(block.timestamp <= roundEndTime, "error: round has ended");
                 _;
                }
                // --- Data ---
                /// @notice Voting Strategy Contract Address
                IVotingStrategy public votingStrategy;
                /// @notice Payout Strategy Contract Address
                IPayoutStrategy public payoutStrategy;
                /// @notice Unix timestamp from when round can accept applications
                uint256 public applicationsStartTime;
                /// @notice Unix timestamp from when round stops accepting applications
                uint256 public applicationsEndTime;
                /// @notice Unix timestamp of the start of the round
                uint256 public roundStartTime;
                /// @notice Unix timestamp of the end of the round
                uint256 public roundEndTime;
                /// @notice Token used to payout match amounts at the end of a round
                IERC20 public token;
                /// @notice MetaPtr to the round metadata
                MetaPtr public roundMetaPtr;
                /// @notice MetaPtr to the application form schema
                MetaPtr public applicationMetaPtr;
                /// @notice MetaPtr to the projects
                MetaPtr public projectsMetaPtr;
                // --- Core methods ---
                /**
                 * @notice Instantiates a new round
                 * @param encodedParameters Encoded parameters for program creation
                 * @dev encodedParameters
                 *  - _votingStrategy Deployed voting strategy contract
                 *  - _payoutStrategy Deployed payout strategy contract
                 *  - _applicationsStartTime Unix timestamp from when round can accept applications
                 *  - _applicationsEndTime Unix timestamp from when round stops accepting applications
                 *  - _roundStartTime Unix timestamp of the start of the round
                 *  - _roundEndTime Unix timestamp of the end of the round
                 *  - _token Address of the ERC20 token for accepting matching pool contributions
                 *  - _roundMetaPtr MetaPtr to the round metadata
                 *  - _applicationMetaPtr MetaPtr to the application form schema
                 *  - _adminRoles Addresses to be granted DEFAULT_ADMIN_ROLE
                 *  - _roundOperators Addresses to be granted ROUND_OPERATOR_ROLE
                 */
                function initialize(
                  bytes calldata encodedParameters
                ) external initializer {
                  // Decode _encodedParameters
                  (
                    IVotingStrategy _votingStrategy,
                    IPayoutStrategy _payoutStrategy,
                    uint256 _applicationsStartTime,
                    uint256 _applicationsEndTime,
                    uint256 _roundStartTime,
                    uint256 _roundEndTime,
                    IERC20 _token,
                    MetaPtr memory _roundMetaPtr,
                    MetaPtr memory _applicationMetaPtr,
                    address[] memory _adminRoles,
                    address[] memory _roundOperators
                  ) = abi.decode(
                    encodedParameters, (
                    IVotingStrategy,
                    IPayoutStrategy,
                    uint256,
                    uint256,
                    uint256,
                    uint256,
                    IERC20,
                    MetaPtr,
                    MetaPtr,
                    address[],
                    address[]
                  ));
                  // slither-disable-next-line timestamp
                  require(_applicationsStartTime >= block.timestamp, "initialize: applications start time has already passed");
                  require(_applicationsEndTime > _applicationsStartTime, "initialize: application end time should be after application start time");
                  require(_roundEndTime >= _applicationsEndTime, "initialize: application end time should be before round end time");
                  require(_roundEndTime > _roundStartTime, "initialize: end time should be after start time");
                  require(_roundStartTime >= _applicationsStartTime, "initialize: round start time should be after application start time");
                  votingStrategy = _votingStrategy;
                  payoutStrategy = _payoutStrategy;
                  applicationsStartTime = _applicationsStartTime;
                  applicationsEndTime = _applicationsEndTime;
                  roundStartTime = _roundStartTime;
                  roundEndTime = _roundEndTime;
                  token = _token;
                  // Invoke init on voting contract
                  votingStrategy.init();
                  // Invoke init on payout contract
                  payoutStrategy.init();
                  // Emit RoundMetaPtrUpdated event for indexing
                  emit RoundMetaPtrUpdated(roundMetaPtr, _roundMetaPtr);
                  roundMetaPtr = _roundMetaPtr;
                  // Emit ApplicationMetaPtrUpdated event for indexing
                  emit ApplicationMetaPtrUpdated(applicationMetaPtr, _applicationMetaPtr);
                  applicationMetaPtr = _applicationMetaPtr;
                  // Assigning default admin role
                  for (uint256 i = 0; i < _adminRoles.length; ++i) {
                    _grantRole(DEFAULT_ADMIN_ROLE, _adminRoles[i]);
                  }
                  // Assigning round operators
                  for (uint256 i = 0; i < _roundOperators.length; ++i) {
                    _grantRole(ROUND_OPERATOR_ROLE, _roundOperators[i]);
                  }
                }
                // @notice Update roundMetaPtr (only by ROUND_OPERATOR_ROLE)
                /// @param newRoundMetaPtr new roundMetaPtr
                function updateRoundMetaPtr(MetaPtr memory newRoundMetaPtr) external roundHasNotEnded onlyRole(ROUND_OPERATOR_ROLE) {
                  emit RoundMetaPtrUpdated(roundMetaPtr, newRoundMetaPtr);
                  roundMetaPtr = newRoundMetaPtr;
                }
                // @notice Update applicationMetaPtr (only by ROUND_OPERATOR_ROLE)
                /// @param newApplicationMetaPtr new applicationMetaPtr
                function updateApplicationMetaPtr(MetaPtr memory newApplicationMetaPtr) external roundHasNotEnded onlyRole(ROUND_OPERATOR_ROLE) {
                  emit ApplicationMetaPtrUpdated(applicationMetaPtr, newApplicationMetaPtr);
                  applicationMetaPtr = newApplicationMetaPtr;
                }
                /// @notice Update roundStartTime (only by ROUND_OPERATOR_ROLE)
                /// @param newRoundStartTime new roundStartTime
                function updateRoundStartTime(uint256 newRoundStartTime) external roundHasNotEnded onlyRole(ROUND_OPERATOR_ROLE) {
                  // slither-disable-next-line timestamp
                  require(newRoundStartTime >= block.timestamp, "updateRoundStartTime: start time has already passed");
                  require(newRoundStartTime >= applicationsStartTime, "updateRoundStartTime: start time should be after application start time");
                  require(newRoundStartTime < roundEndTime, "updateRoundStartTime: start time should be before round end time");
                  emit RoundStartTimeUpdated(roundStartTime, newRoundStartTime);
                  roundStartTime = newRoundStartTime;
                }
                /// @notice Update roundEndTime (only by ROUND_OPERATOR_ROLE)
                /// @param newRoundEndTime new roundEndTime
                function updateRoundEndTime(uint256 newRoundEndTime) external roundHasNotEnded onlyRole(ROUND_OPERATOR_ROLE) {
                  // slither-disable-next-line timestamp
                  require(newRoundEndTime >= block.timestamp, "updateRoundEndTime: end time has already passed");
                  require(newRoundEndTime > roundStartTime, "updateRoundEndTime: end time should be after start time");
                  require(newRoundEndTime >= applicationsEndTime, "updateRoundEndTime: end time should be after application end time");
                  emit RoundEndTimeUpdated(roundEndTime, newRoundEndTime);
                  roundEndTime = newRoundEndTime;
                }
                /// @notice Update applicationsStartTime (only by ROUND_OPERATOR_ROLE)
                /// @param newApplicationsStartTime new applicationsStartTime
                function updateApplicationsStartTime(uint256 newApplicationsStartTime) external roundHasNotEnded onlyRole(ROUND_OPERATOR_ROLE) {
                  // slither-disable-next-line timestamp
                  require(newApplicationsStartTime >= block.timestamp, "updateApplicationsStartTime: application start time has already passed");
                  require(newApplicationsStartTime <= roundStartTime, "updateApplicationsStartTime: should be before round start time");
                  require(newApplicationsStartTime < applicationsEndTime, "updateApplicationsStartTime: should be before application end time");
                  emit ApplicationsStartTimeUpdated(applicationsStartTime, newApplicationsStartTime);
                  applicationsStartTime = newApplicationsStartTime;
                }
                /// @notice Update applicationsEndTime (only by ROUND_OPERATOR_ROLE)
                /// @param newApplicationsEndTime new applicationsEndTime
                function updateApplicationsEndTime(uint256 newApplicationsEndTime) external roundHasNotEnded onlyRole(ROUND_OPERATOR_ROLE) {
                  // slither-disable-next-line timestamp
                  require(newApplicationsEndTime >= block.timestamp, "updateApplicationsEndTime: application end time has already passed");
                  require(newApplicationsEndTime > applicationsStartTime, "updateApplicationsEndTime: application end time should be after application start time");
                  require(newApplicationsEndTime <= roundEndTime, "updateApplicationsEndTime: should be before round end time");
                  emit ApplicationsEndTimeUpdated(applicationsEndTime, newApplicationsEndTime);
                  applicationsEndTime = newApplicationsEndTime;
                }
                /// @notice Update projectsMetaPtr (only by ROUND_OPERATOR_ROLE)
                /// @param newProjectsMetaPtr new ProjectsMetaPtr
                function updateProjectsMetaPtr(MetaPtr calldata newProjectsMetaPtr) external roundHasNotEnded onlyRole(ROUND_OPERATOR_ROLE) {
                  emit ProjectsMetaPtrUpdated(projectsMetaPtr, newProjectsMetaPtr);
                  projectsMetaPtr = newProjectsMetaPtr;
                }
                /// @notice Submit a project application
                /// @param projectID unique hash of the project
                /// @param newApplicationMetaPtr appliction metaPtr
                function applyToRound(bytes32 projectID, MetaPtr calldata newApplicationMetaPtr) external {
                  // slither-disable-next-line timestamp
                  require(
                    applicationsStartTime <= block.timestamp  &&
                    block.timestamp <= applicationsEndTime,
                    "applyToRound: round is not accepting application"
                  );
                  emit NewProjectApplication(projectID, newApplicationMetaPtr);
                }
                /// @notice Invoked by voter to cast votes
                /// @param encodedVotes encoded vote
                /// @dev value is to handle native token voting
                function vote(bytes[] memory encodedVotes) external payable {
                  // slither-disable-next-line timestamp
                  require(
                    roundStartTime <= block.timestamp &&
                    block.timestamp <= roundEndTime,
                    "vote: round is not active"
                  );
                  votingStrategy.vote{value: msg.value}(encodedVotes, msg.sender);
                }
                /// @notice Invoked by round operator to update distribution on payout contract
                /// @param encodedDistribution encoded distribution
                function updateDistribution(bytes memory encodedDistribution) external onlyRole(ROUND_OPERATOR_ROLE) {
                  payoutStrategy.updateDistribution(encodedDistribution);
                }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts (last updated v4.5.0) (access/AccessControlEnumerable.sol)
              pragma solidity ^0.8.0;
              import "./IAccessControlEnumerable.sol";
              import "./AccessControl.sol";
              import "../utils/structs/EnumerableSet.sol";
              /**
               * @dev Extension of {AccessControl} that allows enumerating the members of each role.
               */
              abstract contract AccessControlEnumerable is IAccessControlEnumerable, AccessControl {
                  using EnumerableSet for EnumerableSet.AddressSet;
                  mapping(bytes32 => EnumerableSet.AddressSet) private _roleMembers;
                  /**
                   * @dev See {IERC165-supportsInterface}.
                   */
                  function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
                      return interfaceId == type(IAccessControlEnumerable).interfaceId || super.supportsInterface(interfaceId);
                  }
                  /**
                   * @dev Returns one of the accounts that have `role`. `index` must be a
                   * value between 0 and {getRoleMemberCount}, non-inclusive.
                   *
                   * Role bearers are not sorted in any particular way, and their ordering may
                   * change at any point.
                   *
                   * WARNING: When using {getRoleMember} and {getRoleMemberCount}, make sure
                   * you perform all queries on the same block. See the following
                   * https://forum.openzeppelin.com/t/iterating-over-elements-on-enumerableset-in-openzeppelin-contracts/2296[forum post]
                   * for more information.
                   */
                  function getRoleMember(bytes32 role, uint256 index) public view virtual override returns (address) {
                      return _roleMembers[role].at(index);
                  }
                  /**
                   * @dev Returns the number of accounts that have `role`. Can be used
                   * together with {getRoleMember} to enumerate all bearers of a role.
                   */
                  function getRoleMemberCount(bytes32 role) public view virtual override returns (uint256) {
                      return _roleMembers[role].length();
                  }
                  /**
                   * @dev Overload {_grantRole} to track enumerable memberships
                   */
                  function _grantRole(bytes32 role, address account) internal virtual override {
                      super._grantRole(role, account);
                      _roleMembers[role].add(account);
                  }
                  /**
                   * @dev Overload {_revokeRole} to track enumerable memberships
                   */
                  function _revokeRole(bytes32 role, address account) internal virtual override {
                      super._revokeRole(role, account);
                      _roleMembers[role].remove(account);
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)
              pragma solidity ^0.8.0;
              import "../IERC20.sol";
              import "../../../utils/Address.sol";
              /**
               * @title SafeERC20
               * @dev Wrappers around ERC20 operations that throw on failure (when the token
               * contract returns false). Tokens that return no value (and instead revert or
               * throw on failure) are also supported, non-reverting calls are assumed to be
               * successful.
               * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
               * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
               */
              library SafeERC20 {
                  using Address for address;
                  function safeTransfer(
                      IERC20 token,
                      address to,
                      uint256 value
                  ) internal {
                      _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
                  }
                  function safeTransferFrom(
                      IERC20 token,
                      address from,
                      address to,
                      uint256 value
                  ) internal {
                      _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
                  }
                  /**
                   * @dev Deprecated. This function has issues similar to the ones found in
                   * {IERC20-approve}, and its usage is discouraged.
                   *
                   * Whenever possible, use {safeIncreaseAllowance} and
                   * {safeDecreaseAllowance} instead.
                   */
                  function safeApprove(
                      IERC20 token,
                      address spender,
                      uint256 value
                  ) internal {
                      // safeApprove should only be called when setting an initial allowance,
                      // or when resetting it to zero. To increase and decrease it, use
                      // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
                      require(
                          (value == 0) || (token.allowance(address(this), spender) == 0),
                          "SafeERC20: approve from non-zero to non-zero allowance"
                      );
                      _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
                  }
                  function safeIncreaseAllowance(
                      IERC20 token,
                      address spender,
                      uint256 value
                  ) internal {
                      uint256 newAllowance = token.allowance(address(this), spender) + value;
                      _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
                  }
                  function safeDecreaseAllowance(
                      IERC20 token,
                      address spender,
                      uint256 value
                  ) internal {
                      unchecked {
                          uint256 oldAllowance = token.allowance(address(this), spender);
                          require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
                          uint256 newAllowance = oldAllowance - value;
                          _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
                      }
                  }
                  /**
                   * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
                   * on the return value: the return value is optional (but if data is returned, it must not be false).
                   * @param token The token targeted by the call.
                   * @param data The call data (encoded using abi.encode or one of its variants).
                   */
                  function _callOptionalReturn(IERC20 token, bytes memory data) private {
                      // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
                      // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
                      // the target address contains contract code and also asserts for success in the low-level call.
                      bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
                      if (returndata.length > 0) {
                          // Return data is optional
                          require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
                      }
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)
              pragma solidity ^0.8.1;
              /**
               * @dev Collection of functions related to the address type
               */
              library Address {
                  /**
                   * @dev Returns true if `account` is a contract.
                   *
                   * [IMPORTANT]
                   * ====
                   * It is unsafe to assume that an address for which this function returns
                   * false is an externally-owned account (EOA) and not a contract.
                   *
                   * Among others, `isContract` will return false for the following
                   * types of addresses:
                   *
                   *  - an externally-owned account
                   *  - a contract in construction
                   *  - an address where a contract will be created
                   *  - an address where a contract lived, but was destroyed
                   * ====
                   *
                   * [IMPORTANT]
                   * ====
                   * You shouldn't rely on `isContract` to protect against flash loan attacks!
                   *
                   * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
                   * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
                   * constructor.
                   * ====
                   */
                  function isContract(address account) internal view returns (bool) {
                      // This method relies on extcodesize/address.code.length, which returns 0
                      // for contracts in construction, since the code is only stored at the end
                      // of the constructor execution.
                      return account.code.length > 0;
                  }
                  /**
                   * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
                   * `recipient`, forwarding all available gas and reverting on errors.
                   *
                   * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
                   * of certain opcodes, possibly making contracts go over the 2300 gas limit
                   * imposed by `transfer`, making them unable to receive funds via
                   * `transfer`. {sendValue} removes this limitation.
                   *
                   * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
                   *
                   * IMPORTANT: because control is transferred to `recipient`, care must be
                   * taken to not create reentrancy vulnerabilities. Consider using
                   * {ReentrancyGuard} or the
                   * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
                   */
                  function sendValue(address payable recipient, uint256 amount) internal {
                      require(address(this).balance >= amount, "Address: insufficient balance");
                      (bool success, ) = recipient.call{value: amount}("");
                      require(success, "Address: unable to send value, recipient may have reverted");
                  }
                  /**
                   * @dev Performs a Solidity function call using a low level `call`. A
                   * plain `call` is an unsafe replacement for a function call: use this
                   * function instead.
                   *
                   * If `target` reverts with a revert reason, it is bubbled up by this
                   * function (like regular Solidity function calls).
                   *
                   * Returns the raw returned data. To convert to the expected return value,
                   * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
                   *
                   * Requirements:
                   *
                   * - `target` must be a contract.
                   * - calling `target` with `data` must not revert.
                   *
                   * _Available since v3.1._
                   */
                  function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                      return functionCall(target, data, "Address: low-level call failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
                   * `errorMessage` as a fallback revert reason when `target` reverts.
                   *
                   * _Available since v3.1._
                   */
                  function functionCall(
                      address target,
                      bytes memory data,
                      string memory errorMessage
                  ) internal returns (bytes memory) {
                      return functionCallWithValue(target, data, 0, errorMessage);
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                   * but also transferring `value` wei to `target`.
                   *
                   * Requirements:
                   *
                   * - the calling contract must have an ETH balance of at least `value`.
                   * - the called Solidity function must be `payable`.
                   *
                   * _Available since v3.1._
                   */
                  function functionCallWithValue(
                      address target,
                      bytes memory data,
                      uint256 value
                  ) internal returns (bytes memory) {
                      return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
                   * with `errorMessage` as a fallback revert reason when `target` reverts.
                   *
                   * _Available since v3.1._
                   */
                  function functionCallWithValue(
                      address target,
                      bytes memory data,
                      uint256 value,
                      string memory errorMessage
                  ) internal returns (bytes memory) {
                      require(address(this).balance >= value, "Address: insufficient balance for call");
                      require(isContract(target), "Address: call to non-contract");
                      (bool success, bytes memory returndata) = target.call{value: value}(data);
                      return verifyCallResult(success, returndata, errorMessage);
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                   * but performing a static call.
                   *
                   * _Available since v3.3._
                   */
                  function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                      return functionStaticCall(target, data, "Address: low-level static call failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                   * but performing a static call.
                   *
                   * _Available since v3.3._
                   */
                  function functionStaticCall(
                      address target,
                      bytes memory data,
                      string memory errorMessage
                  ) internal view returns (bytes memory) {
                      require(isContract(target), "Address: static call to non-contract");
                      (bool success, bytes memory returndata) = target.staticcall(data);
                      return verifyCallResult(success, returndata, errorMessage);
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                   * but performing a delegate call.
                   *
                   * _Available since v3.4._
                   */
                  function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
                      return functionDelegateCall(target, data, "Address: low-level delegate call failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                   * but performing a delegate call.
                   *
                   * _Available since v3.4._
                   */
                  function functionDelegateCall(
                      address target,
                      bytes memory data,
                      string memory errorMessage
                  ) internal returns (bytes memory) {
                      require(isContract(target), "Address: delegate call to non-contract");
                      (bool success, bytes memory returndata) = target.delegatecall(data);
                      return verifyCallResult(success, returndata, errorMessage);
                  }
                  /**
                   * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
                   * revert reason using the provided one.
                   *
                   * _Available since v4.3._
                   */
                  function verifyCallResult(
                      bool success,
                      bytes memory returndata,
                      string memory errorMessage
                  ) internal pure returns (bytes memory) {
                      if (success) {
                          return returndata;
                      } else {
                          // Look for revert reason and bubble it up if present
                          if (returndata.length > 0) {
                              // The easiest way to bubble the revert reason is using memory via assembly
                              assembly {
                                  let returndata_size := mload(returndata)
                                  revert(add(32, returndata), returndata_size)
                              }
                          } else {
                              revert(errorMessage);
                          }
                      }
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts (last updated v4.6.0) (proxy/utils/Initializable.sol)
              pragma solidity ^0.8.2;
              import "../../utils/AddressUpgradeable.sol";
              /**
               * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
               * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an
               * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
               * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
               *
               * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be
               * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in
               * case an upgrade adds a module that needs to be initialized.
               *
               * For example:
               *
               * [.hljs-theme-light.nopadding]
               * ```
               * contract MyToken is ERC20Upgradeable {
               *     function initialize() initializer public {
               *         __ERC20_init("MyToken", "MTK");
               *     }
               * }
               * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {
               *     function initializeV2() reinitializer(2) public {
               *         __ERC20Permit_init("MyToken");
               *     }
               * }
               * ```
               *
               * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
               * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
               *
               * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
               * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
               *
               * [CAUTION]
               * ====
               * Avoid leaving a contract uninitialized.
               *
               * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
               * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke
               * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:
               *
               * [.hljs-theme-light.nopadding]
               * ```
               * /// @custom:oz-upgrades-unsafe-allow constructor
               * constructor() {
               *     _disableInitializers();
               * }
               * ```
               * ====
               */
              abstract contract Initializable {
                  /**
                   * @dev Indicates that the contract has been initialized.
                   * @custom:oz-retyped-from bool
                   */
                  uint8 private _initialized;
                  /**
                   * @dev Indicates that the contract is in the process of being initialized.
                   */
                  bool private _initializing;
                  /**
                   * @dev Triggered when the contract has been initialized or reinitialized.
                   */
                  event Initialized(uint8 version);
                  /**
                   * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
                   * `onlyInitializing` functions can be used to initialize parent contracts. Equivalent to `reinitializer(1)`.
                   */
                  modifier initializer() {
                      bool isTopLevelCall = _setInitializedVersion(1);
                      if (isTopLevelCall) {
                          _initializing = true;
                      }
                      _;
                      if (isTopLevelCall) {
                          _initializing = false;
                          emit Initialized(1);
                      }
                  }
                  /**
                   * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
                   * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
                   * used to initialize parent contracts.
                   *
                   * `initializer` is equivalent to `reinitializer(1)`, so a reinitializer may be used after the original
                   * initialization step. This is essential to configure modules that are added through upgrades and that require
                   * initialization.
                   *
                   * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
                   * a contract, executing them in the right order is up to the developer or operator.
                   */
                  modifier reinitializer(uint8 version) {
                      bool isTopLevelCall = _setInitializedVersion(version);
                      if (isTopLevelCall) {
                          _initializing = true;
                      }
                      _;
                      if (isTopLevelCall) {
                          _initializing = false;
                          emit Initialized(version);
                      }
                  }
                  /**
                   * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
                   * {initializer} and {reinitializer} modifiers, directly or indirectly.
                   */
                  modifier onlyInitializing() {
                      require(_initializing, "Initializable: contract is not initializing");
                      _;
                  }
                  /**
                   * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.
                   * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized
                   * to any version. It is recommended to use this to lock implementation contracts that are designed to be called
                   * through proxies.
                   */
                  function _disableInitializers() internal virtual {
                      _setInitializedVersion(type(uint8).max);
                  }
                  function _setInitializedVersion(uint8 version) private returns (bool) {
                      // If the contract is initializing we ignore whether _initialized is set in order to support multiple
                      // inheritance patterns, but we only do this in the context of a constructor, and for the lowest level
                      // of initializers, because in other contexts the contract may have been reentered.
                      if (_initializing) {
                          require(
                              version == 1 && !AddressUpgradeable.isContract(address(this)),
                              "Initializable: contract is already initialized"
                          );
                          return false;
                      } else {
                          require(_initialized < version, "Initializable: contract is already initialized");
                          _initialized = version;
                          return true;
                      }
                  }
              }
              // SPDX-License-Identifier: AGPL-3.0-only
              pragma solidity 0.8.17;
              /**
               * @notice Defines the abstract contract for voting algorithms on grants
               * within a round. Any new voting algorithm would be expected to
               * extend this abstract contract.
               * Every IVotingStrategy contract would be unique to RoundImplementation
               * and would be deployed before creating a round
               */
              abstract contract IVotingStrategy {
                 // --- Data ---
                /// @notice Round address
                address public roundAddress;
                // --- Modifier ---
                /// @notice modifier to check if sender is round contract.
                modifier isRoundContract() {
                  require(roundAddress != address(0), "error: voting contract not linked to a round");
                  require(msg.sender == roundAddress, "error: can be invoked only by round contract");
                  _;
                }
                // --- Core methods ---
                /**
                 * @notice Invoked by RoundImplementation on creation to
                 * set the round for which the voting contracts is to be used
                 *
                 */
                function init() external {
                  require(roundAddress == address(0), "init: roundAddress already set");
                  roundAddress = msg.sender;
                }
                /**
                 * @notice Invoked by RoundImplementation to allow voter to case
                 * vote for grants during a round.
                 *
                 * @dev
                 * - allows contributor to do cast multiple votes which could be weighted.
                 * - should be invoked by RoundImplementation contract
                 * - ideally IVotingStrategy implementation should emit events after a vote is cast
                 * - this would be triggered when a voter casts their vote via grant explorer
                 *
                 * @param _encodedVotes encoded votes
                 * @param _voterAddress voter address
                 */
                function vote(bytes[] calldata _encodedVotes, address _voterAddress) external virtual payable;
              }
              // SPDX-License-Identifier: AGPL-3.0-only
              pragma solidity 0.8.17;
              /**
               * @notice Defines the abstract contract for payout strategies
               * for a round. Any new payout strategy would be expected to
               * extend this abstract contract.
               * Every IPayoutStrategy contract would be unique to RoundImplementation
               * and would be deployed before creating a round 
               *
               * @dev
               *  - Deployed before creating a round
               *  - init will be invoked during round creation to link the payout
               *    strategy to the round contract 
               *  - TODO: add function distribute() to actually distribute the funds  
               */
              abstract contract IPayoutStrategy {
                 // --- Data ---
                /// @notice Round address
                address public roundAddress;
                // --- Modifier ---
                /// @notice modifier to check if sender is round contract.
                modifier isRoundContract() {
                  require(roundAddress != address(0), "error: payout contract not linked to a round");
                  require(msg.sender == roundAddress, "error: can be invoked only by round contract");
                  _;
                }
                // --- Core methods ---
                /**
                 * @notice Invoked by RoundImplementation on creation to
                 * set the round for which the payout strategy is to be used
                 *
                 */
                function init() external {
                  require(roundAddress == address(0), "init: roundAddress already set");
                  roundAddress = msg.sender;
                }
                /**
                 * @notice Invoked by RoundImplementation to upload distribution to the
                 * payout strategy
                 *
                 * @dev
                 * - should be invoked by RoundImplementation contract
                 * - ideally IPayoutStrategy implementation should emit events after 
                 *   distribution is updated
                 * - would be invoked at the end of the round
                 *
                 * @param _encodedDistribution encoded distribution
                 */
                function updateDistribution(bytes calldata _encodedDistribution) external virtual;
              }
              // SPDX-License-Identifier: AGPL-3.0-only
              pragma solidity 0.8.17;
              struct MetaPtr {
                /// @notice Protocol ID corresponding to a specific protocol.
                /// More info at https://github.com/gitcoinco/grants-round/tree/main/packages/contracts/docs/MetaPtrProtocol.md
                uint256 protocol;
                
                /// @notice Pointer to fetch metadata for the specified protocol
                string pointer;
              }// SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts v4.4.1 (access/IAccessControlEnumerable.sol)
              pragma solidity ^0.8.0;
              import "./IAccessControl.sol";
              /**
               * @dev External interface of AccessControlEnumerable declared to support ERC165 detection.
               */
              interface IAccessControlEnumerable is IAccessControl {
                  /**
                   * @dev Returns one of the accounts that have `role`. `index` must be a
                   * value between 0 and {getRoleMemberCount}, non-inclusive.
                   *
                   * Role bearers are not sorted in any particular way, and their ordering may
                   * change at any point.
                   *
                   * WARNING: When using {getRoleMember} and {getRoleMemberCount}, make sure
                   * you perform all queries on the same block. See the following
                   * https://forum.openzeppelin.com/t/iterating-over-elements-on-enumerableset-in-openzeppelin-contracts/2296[forum post]
                   * for more information.
                   */
                  function getRoleMember(bytes32 role, uint256 index) external view returns (address);
                  /**
                   * @dev Returns the number of accounts that have `role`. Can be used
                   * together with {getRoleMember} to enumerate all bearers of a role.
                   */
                  function getRoleMemberCount(bytes32 role) external view returns (uint256);
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts (last updated v4.6.0) (access/AccessControl.sol)
              pragma solidity ^0.8.0;
              import "./IAccessControl.sol";
              import "../utils/Context.sol";
              import "../utils/Strings.sol";
              import "../utils/introspection/ERC165.sol";
              /**
               * @dev Contract module that allows children to implement role-based access
               * control mechanisms. This is a lightweight version that doesn't allow enumerating role
               * members except through off-chain means by accessing the contract event logs. Some
               * applications may benefit from on-chain enumerability, for those cases see
               * {AccessControlEnumerable}.
               *
               * Roles are referred to by their `bytes32` identifier. These should be exposed
               * in the external API and be unique. The best way to achieve this is by
               * using `public constant` hash digests:
               *
               * ```
               * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
               * ```
               *
               * Roles can be used to represent a set of permissions. To restrict access to a
               * function call, use {hasRole}:
               *
               * ```
               * function foo() public {
               *     require(hasRole(MY_ROLE, msg.sender));
               *     ...
               * }
               * ```
               *
               * Roles can be granted and revoked dynamically via the {grantRole} and
               * {revokeRole} functions. Each role has an associated admin role, and only
               * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
               *
               * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
               * that only accounts with this role will be able to grant or revoke other
               * roles. More complex role relationships can be created by using
               * {_setRoleAdmin}.
               *
               * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
               * grant and revoke this role. Extra precautions should be taken to secure
               * accounts that have been granted it.
               */
              abstract contract AccessControl is Context, IAccessControl, ERC165 {
                  struct RoleData {
                      mapping(address => bool) members;
                      bytes32 adminRole;
                  }
                  mapping(bytes32 => RoleData) private _roles;
                  bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;
                  /**
                   * @dev Modifier that checks that an account has a specific role. Reverts
                   * with a standardized message including the required role.
                   *
                   * The format of the revert reason is given by the following regular expression:
                   *
                   *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
                   *
                   * _Available since v4.1._
                   */
                  modifier onlyRole(bytes32 role) {
                      _checkRole(role);
                      _;
                  }
                  /**
                   * @dev See {IERC165-supportsInterface}.
                   */
                  function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
                      return interfaceId == type(IAccessControl).interfaceId || super.supportsInterface(interfaceId);
                  }
                  /**
                   * @dev Returns `true` if `account` has been granted `role`.
                   */
                  function hasRole(bytes32 role, address account) public view virtual override returns (bool) {
                      return _roles[role].members[account];
                  }
                  /**
                   * @dev Revert with a standard message if `_msgSender()` is missing `role`.
                   * Overriding this function changes the behavior of the {onlyRole} modifier.
                   *
                   * Format of the revert message is described in {_checkRole}.
                   *
                   * _Available since v4.6._
                   */
                  function _checkRole(bytes32 role) internal view virtual {
                      _checkRole(role, _msgSender());
                  }
                  /**
                   * @dev Revert with a standard message if `account` is missing `role`.
                   *
                   * The format of the revert reason is given by the following regular expression:
                   *
                   *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
                   */
                  function _checkRole(bytes32 role, address account) internal view virtual {
                      if (!hasRole(role, account)) {
                          revert(
                              string(
                                  abi.encodePacked(
                                      "AccessControl: account ",
                                      Strings.toHexString(uint160(account), 20),
                                      " is missing role ",
                                      Strings.toHexString(uint256(role), 32)
                                  )
                              )
                          );
                      }
                  }
                  /**
                   * @dev Returns the admin role that controls `role`. See {grantRole} and
                   * {revokeRole}.
                   *
                   * To change a role's admin, use {_setRoleAdmin}.
                   */
                  function getRoleAdmin(bytes32 role) public view virtual override returns (bytes32) {
                      return _roles[role].adminRole;
                  }
                  /**
                   * @dev Grants `role` to `account`.
                   *
                   * If `account` had not been already granted `role`, emits a {RoleGranted}
                   * event.
                   *
                   * Requirements:
                   *
                   * - the caller must have ``role``'s admin role.
                   */
                  function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
                      _grantRole(role, account);
                  }
                  /**
                   * @dev Revokes `role` from `account`.
                   *
                   * If `account` had been granted `role`, emits a {RoleRevoked} event.
                   *
                   * Requirements:
                   *
                   * - the caller must have ``role``'s admin role.
                   */
                  function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
                      _revokeRole(role, account);
                  }
                  /**
                   * @dev Revokes `role` from the calling account.
                   *
                   * Roles are often managed via {grantRole} and {revokeRole}: this function's
                   * purpose is to provide a mechanism for accounts to lose their privileges
                   * if they are compromised (such as when a trusted device is misplaced).
                   *
                   * If the calling account had been revoked `role`, emits a {RoleRevoked}
                   * event.
                   *
                   * Requirements:
                   *
                   * - the caller must be `account`.
                   */
                  function renounceRole(bytes32 role, address account) public virtual override {
                      require(account == _msgSender(), "AccessControl: can only renounce roles for self");
                      _revokeRole(role, account);
                  }
                  /**
                   * @dev Grants `role` to `account`.
                   *
                   * If `account` had not been already granted `role`, emits a {RoleGranted}
                   * event. Note that unlike {grantRole}, this function doesn't perform any
                   * checks on the calling account.
                   *
                   * [WARNING]
                   * ====
                   * This function should only be called from the constructor when setting
                   * up the initial roles for the system.
                   *
                   * Using this function in any other way is effectively circumventing the admin
                   * system imposed by {AccessControl}.
                   * ====
                   *
                   * NOTE: This function is deprecated in favor of {_grantRole}.
                   */
                  function _setupRole(bytes32 role, address account) internal virtual {
                      _grantRole(role, account);
                  }
                  /**
                   * @dev Sets `adminRole` as ``role``'s admin role.
                   *
                   * Emits a {RoleAdminChanged} event.
                   */
                  function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
                      bytes32 previousAdminRole = getRoleAdmin(role);
                      _roles[role].adminRole = adminRole;
                      emit RoleAdminChanged(role, previousAdminRole, adminRole);
                  }
                  /**
                   * @dev Grants `role` to `account`.
                   *
                   * Internal function without access restriction.
                   */
                  function _grantRole(bytes32 role, address account) internal virtual {
                      if (!hasRole(role, account)) {
                          _roles[role].members[account] = true;
                          emit RoleGranted(role, account, _msgSender());
                      }
                  }
                  /**
                   * @dev Revokes `role` from `account`.
                   *
                   * Internal function without access restriction.
                   */
                  function _revokeRole(bytes32 role, address account) internal virtual {
                      if (hasRole(role, account)) {
                          _roles[role].members[account] = false;
                          emit RoleRevoked(role, account, _msgSender());
                      }
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts (last updated v4.6.0) (utils/structs/EnumerableSet.sol)
              pragma solidity ^0.8.0;
              /**
               * @dev Library for managing
               * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
               * types.
               *
               * Sets have the following properties:
               *
               * - Elements are added, removed, and checked for existence in constant time
               * (O(1)).
               * - Elements are enumerated in O(n). No guarantees are made on the ordering.
               *
               * ```
               * contract Example {
               *     // Add the library methods
               *     using EnumerableSet for EnumerableSet.AddressSet;
               *
               *     // Declare a set state variable
               *     EnumerableSet.AddressSet private mySet;
               * }
               * ```
               *
               * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
               * and `uint256` (`UintSet`) are supported.
               */
              library EnumerableSet {
                  // To implement this library for multiple types with as little code
                  // repetition as possible, we write it in terms of a generic Set type with
                  // bytes32 values.
                  // The Set implementation uses private functions, and user-facing
                  // implementations (such as AddressSet) are just wrappers around the
                  // underlying Set.
                  // This means that we can only create new EnumerableSets for types that fit
                  // in bytes32.
                  struct Set {
                      // Storage of set values
                      bytes32[] _values;
                      // Position of the value in the `values` array, plus 1 because index 0
                      // means a value is not in the set.
                      mapping(bytes32 => uint256) _indexes;
                  }
                  /**
                   * @dev Add a value to a set. O(1).
                   *
                   * Returns true if the value was added to the set, that is if it was not
                   * already present.
                   */
                  function _add(Set storage set, bytes32 value) private returns (bool) {
                      if (!_contains(set, value)) {
                          set._values.push(value);
                          // The value is stored at length-1, but we add 1 to all indexes
                          // and use 0 as a sentinel value
                          set._indexes[value] = set._values.length;
                          return true;
                      } else {
                          return false;
                      }
                  }
                  /**
                   * @dev Removes a value from a set. O(1).
                   *
                   * Returns true if the value was removed from the set, that is if it was
                   * present.
                   */
                  function _remove(Set storage set, bytes32 value) private returns (bool) {
                      // We read and store the value's index to prevent multiple reads from the same storage slot
                      uint256 valueIndex = set._indexes[value];
                      if (valueIndex != 0) {
                          // Equivalent to contains(set, value)
                          // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
                          // the array, and then remove the last element (sometimes called as 'swap and pop').
                          // This modifies the order of the array, as noted in {at}.
                          uint256 toDeleteIndex = valueIndex - 1;
                          uint256 lastIndex = set._values.length - 1;
                          if (lastIndex != toDeleteIndex) {
                              bytes32 lastValue = set._values[lastIndex];
                              // Move the last value to the index where the value to delete is
                              set._values[toDeleteIndex] = lastValue;
                              // Update the index for the moved value
                              set._indexes[lastValue] = valueIndex; // Replace lastValue's index to valueIndex
                          }
                          // Delete the slot where the moved value was stored
                          set._values.pop();
                          // Delete the index for the deleted slot
                          delete set._indexes[value];
                          return true;
                      } else {
                          return false;
                      }
                  }
                  /**
                   * @dev Returns true if the value is in the set. O(1).
                   */
                  function _contains(Set storage set, bytes32 value) private view returns (bool) {
                      return set._indexes[value] != 0;
                  }
                  /**
                   * @dev Returns the number of values on the set. O(1).
                   */
                  function _length(Set storage set) private view returns (uint256) {
                      return set._values.length;
                  }
                  /**
                   * @dev Returns the value stored at position `index` in the set. O(1).
                   *
                   * Note that there are no guarantees on the ordering of values inside the
                   * array, and it may change when more values are added or removed.
                   *
                   * Requirements:
                   *
                   * - `index` must be strictly less than {length}.
                   */
                  function _at(Set storage set, uint256 index) private view returns (bytes32) {
                      return set._values[index];
                  }
                  /**
                   * @dev Return the entire set in an array
                   *
                   * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
                   * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
                   * this function has an unbounded cost, and using it as part of a state-changing function may render the function
                   * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
                   */
                  function _values(Set storage set) private view returns (bytes32[] memory) {
                      return set._values;
                  }
                  // Bytes32Set
                  struct Bytes32Set {
                      Set _inner;
                  }
                  /**
                   * @dev Add a value to a set. O(1).
                   *
                   * Returns true if the value was added to the set, that is if it was not
                   * already present.
                   */
                  function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
                      return _add(set._inner, value);
                  }
                  /**
                   * @dev Removes a value from a set. O(1).
                   *
                   * Returns true if the value was removed from the set, that is if it was
                   * present.
                   */
                  function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
                      return _remove(set._inner, value);
                  }
                  /**
                   * @dev Returns true if the value is in the set. O(1).
                   */
                  function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
                      return _contains(set._inner, value);
                  }
                  /**
                   * @dev Returns the number of values in the set. O(1).
                   */
                  function length(Bytes32Set storage set) internal view returns (uint256) {
                      return _length(set._inner);
                  }
                  /**
                   * @dev Returns the value stored at position `index` in the set. O(1).
                   *
                   * Note that there are no guarantees on the ordering of values inside the
                   * array, and it may change when more values are added or removed.
                   *
                   * Requirements:
                   *
                   * - `index` must be strictly less than {length}.
                   */
                  function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
                      return _at(set._inner, index);
                  }
                  /**
                   * @dev Return the entire set in an array
                   *
                   * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
                   * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
                   * this function has an unbounded cost, and using it as part of a state-changing function may render the function
                   * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
                   */
                  function values(Bytes32Set storage set) internal view returns (bytes32[] memory) {
                      return _values(set._inner);
                  }
                  // AddressSet
                  struct AddressSet {
                      Set _inner;
                  }
                  /**
                   * @dev Add a value to a set. O(1).
                   *
                   * Returns true if the value was added to the set, that is if it was not
                   * already present.
                   */
                  function add(AddressSet storage set, address value) internal returns (bool) {
                      return _add(set._inner, bytes32(uint256(uint160(value))));
                  }
                  /**
                   * @dev Removes a value from a set. O(1).
                   *
                   * Returns true if the value was removed from the set, that is if it was
                   * present.
                   */
                  function remove(AddressSet storage set, address value) internal returns (bool) {
                      return _remove(set._inner, bytes32(uint256(uint160(value))));
                  }
                  /**
                   * @dev Returns true if the value is in the set. O(1).
                   */
                  function contains(AddressSet storage set, address value) internal view returns (bool) {
                      return _contains(set._inner, bytes32(uint256(uint160(value))));
                  }
                  /**
                   * @dev Returns the number of values in the set. O(1).
                   */
                  function length(AddressSet storage set) internal view returns (uint256) {
                      return _length(set._inner);
                  }
                  /**
                   * @dev Returns the value stored at position `index` in the set. O(1).
                   *
                   * Note that there are no guarantees on the ordering of values inside the
                   * array, and it may change when more values are added or removed.
                   *
                   * Requirements:
                   *
                   * - `index` must be strictly less than {length}.
                   */
                  function at(AddressSet storage set, uint256 index) internal view returns (address) {
                      return address(uint160(uint256(_at(set._inner, index))));
                  }
                  /**
                   * @dev Return the entire set in an array
                   *
                   * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
                   * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
                   * this function has an unbounded cost, and using it as part of a state-changing function may render the function
                   * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
                   */
                  function values(AddressSet storage set) internal view returns (address[] memory) {
                      bytes32[] memory store = _values(set._inner);
                      address[] memory result;
                      assembly {
                          result := store
                      }
                      return result;
                  }
                  // UintSet
                  struct UintSet {
                      Set _inner;
                  }
                  /**
                   * @dev Add a value to a set. O(1).
                   *
                   * Returns true if the value was added to the set, that is if it was not
                   * already present.
                   */
                  function add(UintSet storage set, uint256 value) internal returns (bool) {
                      return _add(set._inner, bytes32(value));
                  }
                  /**
                   * @dev Removes a value from a set. O(1).
                   *
                   * Returns true if the value was removed from the set, that is if it was
                   * present.
                   */
                  function remove(UintSet storage set, uint256 value) internal returns (bool) {
                      return _remove(set._inner, bytes32(value));
                  }
                  /**
                   * @dev Returns true if the value is in the set. O(1).
                   */
                  function contains(UintSet storage set, uint256 value) internal view returns (bool) {
                      return _contains(set._inner, bytes32(value));
                  }
                  /**
                   * @dev Returns the number of values on the set. O(1).
                   */
                  function length(UintSet storage set) internal view returns (uint256) {
                      return _length(set._inner);
                  }
                  /**
                   * @dev Returns the value stored at position `index` in the set. O(1).
                   *
                   * Note that there are no guarantees on the ordering of values inside the
                   * array, and it may change when more values are added or removed.
                   *
                   * Requirements:
                   *
                   * - `index` must be strictly less than {length}.
                   */
                  function at(UintSet storage set, uint256 index) internal view returns (uint256) {
                      return uint256(_at(set._inner, index));
                  }
                  /**
                   * @dev Return the entire set in an array
                   *
                   * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
                   * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
                   * this function has an unbounded cost, and using it as part of a state-changing function may render the function
                   * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
                   */
                  function values(UintSet storage set) internal view returns (uint256[] memory) {
                      bytes32[] memory store = _values(set._inner);
                      uint256[] memory result;
                      assembly {
                          result := store
                      }
                      return result;
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts v4.4.1 (access/IAccessControl.sol)
              pragma solidity ^0.8.0;
              /**
               * @dev External interface of AccessControl declared to support ERC165 detection.
               */
              interface IAccessControl {
                  /**
                   * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
                   *
                   * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
                   * {RoleAdminChanged} not being emitted signaling this.
                   *
                   * _Available since v3.1._
                   */
                  event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);
                  /**
                   * @dev Emitted when `account` is granted `role`.
                   *
                   * `sender` is the account that originated the contract call, an admin role
                   * bearer except when using {AccessControl-_setupRole}.
                   */
                  event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);
                  /**
                   * @dev Emitted when `account` is revoked `role`.
                   *
                   * `sender` is the account that originated the contract call:
                   *   - if using `revokeRole`, it is the admin role bearer
                   *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
                   */
                  event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);
                  /**
                   * @dev Returns `true` if `account` has been granted `role`.
                   */
                  function hasRole(bytes32 role, address account) external view returns (bool);
                  /**
                   * @dev Returns the admin role that controls `role`. See {grantRole} and
                   * {revokeRole}.
                   *
                   * To change a role's admin, use {AccessControl-_setRoleAdmin}.
                   */
                  function getRoleAdmin(bytes32 role) external view returns (bytes32);
                  /**
                   * @dev Grants `role` to `account`.
                   *
                   * If `account` had not been already granted `role`, emits a {RoleGranted}
                   * event.
                   *
                   * Requirements:
                   *
                   * - the caller must have ``role``'s admin role.
                   */
                  function grantRole(bytes32 role, address account) external;
                  /**
                   * @dev Revokes `role` from `account`.
                   *
                   * If `account` had been granted `role`, emits a {RoleRevoked} event.
                   *
                   * Requirements:
                   *
                   * - the caller must have ``role``'s admin role.
                   */
                  function revokeRole(bytes32 role, address account) external;
                  /**
                   * @dev Revokes `role` from the calling account.
                   *
                   * Roles are often managed via {grantRole} and {revokeRole}: this function's
                   * purpose is to provide a mechanism for accounts to lose their privileges
                   * if they are compromised (such as when a trusted device is misplaced).
                   *
                   * If the calling account had been granted `role`, emits a {RoleRevoked}
                   * event.
                   *
                   * Requirements:
                   *
                   * - the caller must be `account`.
                   */
                  function renounceRole(bytes32 role, address account) external;
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
              pragma solidity ^0.8.0;
              /**
               * @dev Provides information about the current execution context, including the
               * sender of the transaction and its data. While these are generally available
               * via msg.sender and msg.data, they should not be accessed in such a direct
               * manner, since when dealing with meta-transactions the account sending and
               * paying for execution may not be the actual sender (as far as an application
               * is concerned).
               *
               * This contract is only required for intermediate, library-like contracts.
               */
              abstract contract Context {
                  function _msgSender() internal view virtual returns (address) {
                      return msg.sender;
                  }
                  function _msgData() internal view virtual returns (bytes calldata) {
                      return msg.data;
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)
              pragma solidity ^0.8.0;
              /**
               * @dev String operations.
               */
              library Strings {
                  bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
                  /**
                   * @dev Converts a `uint256` to its ASCII `string` decimal representation.
                   */
                  function toString(uint256 value) internal pure returns (string memory) {
                      // Inspired by OraclizeAPI's implementation - MIT licence
                      // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
                      if (value == 0) {
                          return "0";
                      }
                      uint256 temp = value;
                      uint256 digits;
                      while (temp != 0) {
                          digits++;
                          temp /= 10;
                      }
                      bytes memory buffer = new bytes(digits);
                      while (value != 0) {
                          digits -= 1;
                          buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
                          value /= 10;
                      }
                      return string(buffer);
                  }
                  /**
                   * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
                   */
                  function toHexString(uint256 value) internal pure returns (string memory) {
                      if (value == 0) {
                          return "0x00";
                      }
                      uint256 temp = value;
                      uint256 length = 0;
                      while (temp != 0) {
                          length++;
                          temp >>= 8;
                      }
                      return toHexString(value, length);
                  }
                  /**
                   * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
                   */
                  function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
                      bytes memory buffer = new bytes(2 * length + 2);
                      buffer[0] = "0";
                      buffer[1] = "x";
                      for (uint256 i = 2 * length + 1; i > 1; --i) {
                          buffer[i] = _HEX_SYMBOLS[value & 0xf];
                          value >>= 4;
                      }
                      require(value == 0, "Strings: hex length insufficient");
                      return string(buffer);
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
              pragma solidity ^0.8.0;
              import "./IERC165.sol";
              /**
               * @dev Implementation of the {IERC165} interface.
               *
               * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
               * for the additional interface id that will be supported. For example:
               *
               * ```solidity
               * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
               *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
               * }
               * ```
               *
               * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
               */
              abstract contract ERC165 is IERC165 {
                  /**
                   * @dev See {IERC165-supportsInterface}.
                   */
                  function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
                      return interfaceId == type(IERC165).interfaceId;
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
              pragma solidity ^0.8.0;
              /**
               * @dev Interface of the ERC165 standard, as defined in the
               * https://eips.ethereum.org/EIPS/eip-165[EIP].
               *
               * Implementers can declare support of contract interfaces, which can then be
               * queried by others ({ERC165Checker}).
               *
               * For an implementation, see {ERC165}.
               */
              interface IERC165 {
                  /**
                   * @dev Returns true if this contract implements the interface defined by
                   * `interfaceId`. See the corresponding
                   * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
                   * to learn more about how these ids are created.
                   *
                   * This function call must use less than 30 000 gas.
                   */
                  function supportsInterface(bytes4 interfaceId) external view returns (bool);
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)
              pragma solidity ^0.8.0;
              /**
               * @dev Interface of the ERC20 standard as defined in the EIP.
               */
              interface IERC20 {
                  /**
                   * @dev Emitted when `value` tokens are moved from one account (`from`) to
                   * another (`to`).
                   *
                   * Note that `value` may be zero.
                   */
                  event Transfer(address indexed from, address indexed to, uint256 value);
                  /**
                   * @dev Emitted when the allowance of a `spender` for an `owner` is set by
                   * a call to {approve}. `value` is the new allowance.
                   */
                  event Approval(address indexed owner, address indexed spender, uint256 value);
                  /**
                   * @dev Returns the amount of tokens in existence.
                   */
                  function totalSupply() external view returns (uint256);
                  /**
                   * @dev Returns the amount of tokens owned by `account`.
                   */
                  function balanceOf(address account) external view returns (uint256);
                  /**
                   * @dev Moves `amount` tokens from the caller's account to `to`.
                   *
                   * Returns a boolean value indicating whether the operation succeeded.
                   *
                   * Emits a {Transfer} event.
                   */
                  function transfer(address to, uint256 amount) external returns (bool);
                  /**
                   * @dev Returns the remaining number of tokens that `spender` will be
                   * allowed to spend on behalf of `owner` through {transferFrom}. This is
                   * zero by default.
                   *
                   * This value changes when {approve} or {transferFrom} are called.
                   */
                  function allowance(address owner, address spender) external view returns (uint256);
                  /**
                   * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
                   *
                   * Returns a boolean value indicating whether the operation succeeded.
                   *
                   * IMPORTANT: Beware that changing an allowance with this method brings the risk
                   * that someone may use both the old and the new allowance by unfortunate
                   * transaction ordering. One possible solution to mitigate this race
                   * condition is to first reduce the spender's allowance to 0 and set the
                   * desired value afterwards:
                   * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
                   *
                   * Emits an {Approval} event.
                   */
                  function approve(address spender, uint256 amount) external returns (bool);
                  /**
                   * @dev Moves `amount` tokens from `from` to `to` using the
                   * allowance mechanism. `amount` is then deducted from the caller's
                   * allowance.
                   *
                   * Returns a boolean value indicating whether the operation succeeded.
                   *
                   * Emits a {Transfer} event.
                   */
                  function transferFrom(
                      address from,
                      address to,
                      uint256 amount
                  ) external returns (bool);
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)
              pragma solidity ^0.8.1;
              /**
               * @dev Collection of functions related to the address type
               */
              library AddressUpgradeable {
                  /**
                   * @dev Returns true if `account` is a contract.
                   *
                   * [IMPORTANT]
                   * ====
                   * It is unsafe to assume that an address for which this function returns
                   * false is an externally-owned account (EOA) and not a contract.
                   *
                   * Among others, `isContract` will return false for the following
                   * types of addresses:
                   *
                   *  - an externally-owned account
                   *  - a contract in construction
                   *  - an address where a contract will be created
                   *  - an address where a contract lived, but was destroyed
                   * ====
                   *
                   * [IMPORTANT]
                   * ====
                   * You shouldn't rely on `isContract` to protect against flash loan attacks!
                   *
                   * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
                   * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
                   * constructor.
                   * ====
                   */
                  function isContract(address account) internal view returns (bool) {
                      // This method relies on extcodesize/address.code.length, which returns 0
                      // for contracts in construction, since the code is only stored at the end
                      // of the constructor execution.
                      return account.code.length > 0;
                  }
                  /**
                   * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
                   * `recipient`, forwarding all available gas and reverting on errors.
                   *
                   * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
                   * of certain opcodes, possibly making contracts go over the 2300 gas limit
                   * imposed by `transfer`, making them unable to receive funds via
                   * `transfer`. {sendValue} removes this limitation.
                   *
                   * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
                   *
                   * IMPORTANT: because control is transferred to `recipient`, care must be
                   * taken to not create reentrancy vulnerabilities. Consider using
                   * {ReentrancyGuard} or the
                   * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
                   */
                  function sendValue(address payable recipient, uint256 amount) internal {
                      require(address(this).balance >= amount, "Address: insufficient balance");
                      (bool success, ) = recipient.call{value: amount}("");
                      require(success, "Address: unable to send value, recipient may have reverted");
                  }
                  /**
                   * @dev Performs a Solidity function call using a low level `call`. A
                   * plain `call` is an unsafe replacement for a function call: use this
                   * function instead.
                   *
                   * If `target` reverts with a revert reason, it is bubbled up by this
                   * function (like regular Solidity function calls).
                   *
                   * Returns the raw returned data. To convert to the expected return value,
                   * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
                   *
                   * Requirements:
                   *
                   * - `target` must be a contract.
                   * - calling `target` with `data` must not revert.
                   *
                   * _Available since v3.1._
                   */
                  function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                      return functionCall(target, data, "Address: low-level call failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
                   * `errorMessage` as a fallback revert reason when `target` reverts.
                   *
                   * _Available since v3.1._
                   */
                  function functionCall(
                      address target,
                      bytes memory data,
                      string memory errorMessage
                  ) internal returns (bytes memory) {
                      return functionCallWithValue(target, data, 0, errorMessage);
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                   * but also transferring `value` wei to `target`.
                   *
                   * Requirements:
                   *
                   * - the calling contract must have an ETH balance of at least `value`.
                   * - the called Solidity function must be `payable`.
                   *
                   * _Available since v3.1._
                   */
                  function functionCallWithValue(
                      address target,
                      bytes memory data,
                      uint256 value
                  ) internal returns (bytes memory) {
                      return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
                   * with `errorMessage` as a fallback revert reason when `target` reverts.
                   *
                   * _Available since v3.1._
                   */
                  function functionCallWithValue(
                      address target,
                      bytes memory data,
                      uint256 value,
                      string memory errorMessage
                  ) internal returns (bytes memory) {
                      require(address(this).balance >= value, "Address: insufficient balance for call");
                      require(isContract(target), "Address: call to non-contract");
                      (bool success, bytes memory returndata) = target.call{value: value}(data);
                      return verifyCallResult(success, returndata, errorMessage);
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                   * but performing a static call.
                   *
                   * _Available since v3.3._
                   */
                  function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                      return functionStaticCall(target, data, "Address: low-level static call failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                   * but performing a static call.
                   *
                   * _Available since v3.3._
                   */
                  function functionStaticCall(
                      address target,
                      bytes memory data,
                      string memory errorMessage
                  ) internal view returns (bytes memory) {
                      require(isContract(target), "Address: static call to non-contract");
                      (bool success, bytes memory returndata) = target.staticcall(data);
                      return verifyCallResult(success, returndata, errorMessage);
                  }
                  /**
                   * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
                   * revert reason using the provided one.
                   *
                   * _Available since v4.3._
                   */
                  function verifyCallResult(
                      bool success,
                      bytes memory returndata,
                      string memory errorMessage
                  ) internal pure returns (bytes memory) {
                      if (success) {
                          return returndata;
                      } else {
                          // Look for revert reason and bubble it up if present
                          if (returndata.length > 0) {
                              // The easiest way to bubble the revert reason is using memory via assembly
                              assembly {
                                  let returndata_size := mload(returndata)
                                  revert(add(32, returndata), returndata_size)
                              }
                          } else {
                              revert(errorMessage);
                          }
                      }
                  }
              }
              

              File 2 of 7: QuadraticFundingVotingStrategyImplementation
              // SPDX-License-Identifier: AGPL-3.0-only
              pragma solidity 0.8.17;
              import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
              import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
              import "@openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol";
              import "@openzeppelin/contracts-upgradeable/token/ERC20/utils/SafeERC20Upgradeable.sol";
              import "../IVotingStrategy.sol";
              /**
               * Allows voters to cast multiple weighted votes to grants with one transaction
               * This is inspired from BulkCheckout documented over at:
               * https://github.com/gitcoinco/BulkTransactions/blob/master/contracts/BulkCheckout.sol
               *
               * Emits event upon every transfer.
               */
              contract QuadraticFundingVotingStrategyImplementation is IVotingStrategy, ReentrancyGuard, Initializable {
                using SafeERC20Upgradeable for IERC20Upgradeable;
                // --- Event ---
                /// @notice Emitted when a new vote is sent
                event Voted(
                  address  token,                   // voting token
                  uint256 amount,                   // voting amount
                  address indexed voter,            // voter address
                  address indexed grantAddress,     // grant address
                  address indexed roundAddress      // round address
                );
                // --- Core methods ---
                function initialize() external initializer {
                  // empty initializer
                }
                /**
                 * @notice Invoked by RoundImplementation which allows
                 * a voted to cast weighted votes to multiple grants during a round
                 *
                 * @dev
                 * - more voters -> higher the gas
                 * - this would be triggered when a voter casts their vote via grant explorer
                 * - can be invoked by the round
                 * - supports ERC20 and Native token transfer
                 *
                 * @param encodedVotes encoded list of votes
                 * @param voterAddress voter address
                 */
                function vote(bytes[] calldata encodedVotes, address voterAddress) external override payable nonReentrant isRoundContract {
                  /// @dev iterate over multiple donations and transfer funds
                  for (uint256 i = 0; i < encodedVotes.length; i++) {
                    (address _token, uint256 _amount, address _grantAddress) = abi.decode(encodedVotes[i], (address, uint256, address));
                    if (_token == address(0)) {
                      /// @dev native token transfer to grant address
                      // slither-disable-next-line reentrancy-events
                      AddressUpgradeable.sendValue(payable(_grantAddress), _amount);
                    } else {
                      /// @dev erc20 transfer to grant address
                      // slither-disable-next-line arbitrary-send-erc20,reentrancy-events,
                      SafeERC20Upgradeable.safeTransferFrom(
                        IERC20Upgradeable(_token),
                        voterAddress,
                        _grantAddress,
                        _amount
                      );
                    }
                    /// @dev emit event for transfer
                    emit Voted(
                      _token,
                      _amount,
                      voterAddress,
                      _grantAddress,
                      msg.sender
                    );
                  }
                }
              }// SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts (last updated v4.6.0) (proxy/utils/Initializable.sol)
              pragma solidity ^0.8.2;
              import "../../utils/AddressUpgradeable.sol";
              /**
               * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
               * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an
               * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
               * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
               *
               * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be
               * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in
               * case an upgrade adds a module that needs to be initialized.
               *
               * For example:
               *
               * [.hljs-theme-light.nopadding]
               * ```
               * contract MyToken is ERC20Upgradeable {
               *     function initialize() initializer public {
               *         __ERC20_init("MyToken", "MTK");
               *     }
               * }
               * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {
               *     function initializeV2() reinitializer(2) public {
               *         __ERC20Permit_init("MyToken");
               *     }
               * }
               * ```
               *
               * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
               * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
               *
               * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
               * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
               *
               * [CAUTION]
               * ====
               * Avoid leaving a contract uninitialized.
               *
               * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
               * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke
               * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:
               *
               * [.hljs-theme-light.nopadding]
               * ```
               * /// @custom:oz-upgrades-unsafe-allow constructor
               * constructor() {
               *     _disableInitializers();
               * }
               * ```
               * ====
               */
              abstract contract Initializable {
                  /**
                   * @dev Indicates that the contract has been initialized.
                   * @custom:oz-retyped-from bool
                   */
                  uint8 private _initialized;
                  /**
                   * @dev Indicates that the contract is in the process of being initialized.
                   */
                  bool private _initializing;
                  /**
                   * @dev Triggered when the contract has been initialized or reinitialized.
                   */
                  event Initialized(uint8 version);
                  /**
                   * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
                   * `onlyInitializing` functions can be used to initialize parent contracts. Equivalent to `reinitializer(1)`.
                   */
                  modifier initializer() {
                      bool isTopLevelCall = _setInitializedVersion(1);
                      if (isTopLevelCall) {
                          _initializing = true;
                      }
                      _;
                      if (isTopLevelCall) {
                          _initializing = false;
                          emit Initialized(1);
                      }
                  }
                  /**
                   * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
                   * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
                   * used to initialize parent contracts.
                   *
                   * `initializer` is equivalent to `reinitializer(1)`, so a reinitializer may be used after the original
                   * initialization step. This is essential to configure modules that are added through upgrades and that require
                   * initialization.
                   *
                   * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
                   * a contract, executing them in the right order is up to the developer or operator.
                   */
                  modifier reinitializer(uint8 version) {
                      bool isTopLevelCall = _setInitializedVersion(version);
                      if (isTopLevelCall) {
                          _initializing = true;
                      }
                      _;
                      if (isTopLevelCall) {
                          _initializing = false;
                          emit Initialized(version);
                      }
                  }
                  /**
                   * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
                   * {initializer} and {reinitializer} modifiers, directly or indirectly.
                   */
                  modifier onlyInitializing() {
                      require(_initializing, "Initializable: contract is not initializing");
                      _;
                  }
                  /**
                   * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.
                   * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized
                   * to any version. It is recommended to use this to lock implementation contracts that are designed to be called
                   * through proxies.
                   */
                  function _disableInitializers() internal virtual {
                      _setInitializedVersion(type(uint8).max);
                  }
                  function _setInitializedVersion(uint8 version) private returns (bool) {
                      // If the contract is initializing we ignore whether _initialized is set in order to support multiple
                      // inheritance patterns, but we only do this in the context of a constructor, and for the lowest level
                      // of initializers, because in other contexts the contract may have been reentered.
                      if (_initializing) {
                          require(
                              version == 1 && !AddressUpgradeable.isContract(address(this)),
                              "Initializable: contract is already initialized"
                          );
                          return false;
                      } else {
                          require(_initialized < version, "Initializable: contract is already initialized");
                          _initialized = version;
                          return true;
                      }
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)
              pragma solidity ^0.8.0;
              /**
               * @dev Contract module that helps prevent reentrant calls to a function.
               *
               * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
               * available, which can be applied to functions to make sure there are no nested
               * (reentrant) calls to them.
               *
               * Note that because there is a single `nonReentrant` guard, functions marked as
               * `nonReentrant` may not call one another. This can be worked around by making
               * those functions `private`, and then adding `external` `nonReentrant` entry
               * points to them.
               *
               * TIP: If you would like to learn more about reentrancy and alternative ways
               * to protect against it, check out our blog post
               * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
               */
              abstract contract ReentrancyGuard {
                  // Booleans are more expensive than uint256 or any type that takes up a full
                  // word because each write operation emits an extra SLOAD to first read the
                  // slot's contents, replace the bits taken up by the boolean, and then write
                  // back. This is the compiler's defense against contract upgrades and
                  // pointer aliasing, and it cannot be disabled.
                  // The values being non-zero value makes deployment a bit more expensive,
                  // but in exchange the refund on every call to nonReentrant will be lower in
                  // amount. Since refunds are capped to a percentage of the total
                  // transaction's gas, it is best to keep them low in cases like this one, to
                  // increase the likelihood of the full refund coming into effect.
                  uint256 private constant _NOT_ENTERED = 1;
                  uint256 private constant _ENTERED = 2;
                  uint256 private _status;
                  constructor() {
                      _status = _NOT_ENTERED;
                  }
                  /**
                   * @dev Prevents a contract from calling itself, directly or indirectly.
                   * Calling a `nonReentrant` function from another `nonReentrant`
                   * function is not supported. It is possible to prevent this from happening
                   * by making the `nonReentrant` function external, and making it call a
                   * `private` function that does the actual work.
                   */
                  modifier nonReentrant() {
                      // On the first call to nonReentrant, _notEntered will be true
                      require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
                      // Any calls to nonReentrant after this point will fail
                      _status = _ENTERED;
                      _;
                      // By storing the original value once again, a refund is triggered (see
                      // https://eips.ethereum.org/EIPS/eip-2200)
                      _status = _NOT_ENTERED;
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)
              pragma solidity ^0.8.1;
              /**
               * @dev Collection of functions related to the address type
               */
              library AddressUpgradeable {
                  /**
                   * @dev Returns true if `account` is a contract.
                   *
                   * [IMPORTANT]
                   * ====
                   * It is unsafe to assume that an address for which this function returns
                   * false is an externally-owned account (EOA) and not a contract.
                   *
                   * Among others, `isContract` will return false for the following
                   * types of addresses:
                   *
                   *  - an externally-owned account
                   *  - a contract in construction
                   *  - an address where a contract will be created
                   *  - an address where a contract lived, but was destroyed
                   * ====
                   *
                   * [IMPORTANT]
                   * ====
                   * You shouldn't rely on `isContract` to protect against flash loan attacks!
                   *
                   * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
                   * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
                   * constructor.
                   * ====
                   */
                  function isContract(address account) internal view returns (bool) {
                      // This method relies on extcodesize/address.code.length, which returns 0
                      // for contracts in construction, since the code is only stored at the end
                      // of the constructor execution.
                      return account.code.length > 0;
                  }
                  /**
                   * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
                   * `recipient`, forwarding all available gas and reverting on errors.
                   *
                   * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
                   * of certain opcodes, possibly making contracts go over the 2300 gas limit
                   * imposed by `transfer`, making them unable to receive funds via
                   * `transfer`. {sendValue} removes this limitation.
                   *
                   * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
                   *
                   * IMPORTANT: because control is transferred to `recipient`, care must be
                   * taken to not create reentrancy vulnerabilities. Consider using
                   * {ReentrancyGuard} or the
                   * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
                   */
                  function sendValue(address payable recipient, uint256 amount) internal {
                      require(address(this).balance >= amount, "Address: insufficient balance");
                      (bool success, ) = recipient.call{value: amount}("");
                      require(success, "Address: unable to send value, recipient may have reverted");
                  }
                  /**
                   * @dev Performs a Solidity function call using a low level `call`. A
                   * plain `call` is an unsafe replacement for a function call: use this
                   * function instead.
                   *
                   * If `target` reverts with a revert reason, it is bubbled up by this
                   * function (like regular Solidity function calls).
                   *
                   * Returns the raw returned data. To convert to the expected return value,
                   * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
                   *
                   * Requirements:
                   *
                   * - `target` must be a contract.
                   * - calling `target` with `data` must not revert.
                   *
                   * _Available since v3.1._
                   */
                  function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                      return functionCall(target, data, "Address: low-level call failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
                   * `errorMessage` as a fallback revert reason when `target` reverts.
                   *
                   * _Available since v3.1._
                   */
                  function functionCall(
                      address target,
                      bytes memory data,
                      string memory errorMessage
                  ) internal returns (bytes memory) {
                      return functionCallWithValue(target, data, 0, errorMessage);
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                   * but also transferring `value` wei to `target`.
                   *
                   * Requirements:
                   *
                   * - the calling contract must have an ETH balance of at least `value`.
                   * - the called Solidity function must be `payable`.
                   *
                   * _Available since v3.1._
                   */
                  function functionCallWithValue(
                      address target,
                      bytes memory data,
                      uint256 value
                  ) internal returns (bytes memory) {
                      return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
                   * with `errorMessage` as a fallback revert reason when `target` reverts.
                   *
                   * _Available since v3.1._
                   */
                  function functionCallWithValue(
                      address target,
                      bytes memory data,
                      uint256 value,
                      string memory errorMessage
                  ) internal returns (bytes memory) {
                      require(address(this).balance >= value, "Address: insufficient balance for call");
                      require(isContract(target), "Address: call to non-contract");
                      (bool success, bytes memory returndata) = target.call{value: value}(data);
                      return verifyCallResult(success, returndata, errorMessage);
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                   * but performing a static call.
                   *
                   * _Available since v3.3._
                   */
                  function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                      return functionStaticCall(target, data, "Address: low-level static call failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                   * but performing a static call.
                   *
                   * _Available since v3.3._
                   */
                  function functionStaticCall(
                      address target,
                      bytes memory data,
                      string memory errorMessage
                  ) internal view returns (bytes memory) {
                      require(isContract(target), "Address: static call to non-contract");
                      (bool success, bytes memory returndata) = target.staticcall(data);
                      return verifyCallResult(success, returndata, errorMessage);
                  }
                  /**
                   * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
                   * revert reason using the provided one.
                   *
                   * _Available since v4.3._
                   */
                  function verifyCallResult(
                      bool success,
                      bytes memory returndata,
                      string memory errorMessage
                  ) internal pure returns (bytes memory) {
                      if (success) {
                          return returndata;
                      } else {
                          // Look for revert reason and bubble it up if present
                          if (returndata.length > 0) {
                              // The easiest way to bubble the revert reason is using memory via assembly
                              assembly {
                                  let returndata_size := mload(returndata)
                                  revert(add(32, returndata), returndata_size)
                              }
                          } else {
                              revert(errorMessage);
                          }
                      }
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)
              pragma solidity ^0.8.0;
              import "../IERC20Upgradeable.sol";
              import "../../../utils/AddressUpgradeable.sol";
              /**
               * @title SafeERC20
               * @dev Wrappers around ERC20 operations that throw on failure (when the token
               * contract returns false). Tokens that return no value (and instead revert or
               * throw on failure) are also supported, non-reverting calls are assumed to be
               * successful.
               * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
               * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
               */
              library SafeERC20Upgradeable {
                  using AddressUpgradeable for address;
                  function safeTransfer(
                      IERC20Upgradeable token,
                      address to,
                      uint256 value
                  ) internal {
                      _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
                  }
                  function safeTransferFrom(
                      IERC20Upgradeable token,
                      address from,
                      address to,
                      uint256 value
                  ) internal {
                      _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
                  }
                  /**
                   * @dev Deprecated. This function has issues similar to the ones found in
                   * {IERC20-approve}, and its usage is discouraged.
                   *
                   * Whenever possible, use {safeIncreaseAllowance} and
                   * {safeDecreaseAllowance} instead.
                   */
                  function safeApprove(
                      IERC20Upgradeable token,
                      address spender,
                      uint256 value
                  ) internal {
                      // safeApprove should only be called when setting an initial allowance,
                      // or when resetting it to zero. To increase and decrease it, use
                      // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
                      require(
                          (value == 0) || (token.allowance(address(this), spender) == 0),
                          "SafeERC20: approve from non-zero to non-zero allowance"
                      );
                      _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
                  }
                  function safeIncreaseAllowance(
                      IERC20Upgradeable token,
                      address spender,
                      uint256 value
                  ) internal {
                      uint256 newAllowance = token.allowance(address(this), spender) + value;
                      _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
                  }
                  function safeDecreaseAllowance(
                      IERC20Upgradeable token,
                      address spender,
                      uint256 value
                  ) internal {
                      unchecked {
                          uint256 oldAllowance = token.allowance(address(this), spender);
                          require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
                          uint256 newAllowance = oldAllowance - value;
                          _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
                      }
                  }
                  /**
                   * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
                   * on the return value: the return value is optional (but if data is returned, it must not be false).
                   * @param token The token targeted by the call.
                   * @param data The call data (encoded using abi.encode or one of its variants).
                   */
                  function _callOptionalReturn(IERC20Upgradeable token, bytes memory data) private {
                      // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
                      // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
                      // the target address contains contract code and also asserts for success in the low-level call.
                      bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
                      if (returndata.length > 0) {
                          // Return data is optional
                          require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
                      }
                  }
              }
              // SPDX-License-Identifier: AGPL-3.0-only
              pragma solidity 0.8.17;
              /**
               * @notice Defines the abstract contract for voting algorithms on grants
               * within a round. Any new voting algorithm would be expected to
               * extend this abstract contract.
               * Every IVotingStrategy contract would be unique to RoundImplementation
               * and would be deployed before creating a round
               */
              abstract contract IVotingStrategy {
                 // --- Data ---
                /// @notice Round address
                address public roundAddress;
                // --- Modifier ---
                /// @notice modifier to check if sender is round contract.
                modifier isRoundContract() {
                  require(roundAddress != address(0), "error: voting contract not linked to a round");
                  require(msg.sender == roundAddress, "error: can be invoked only by round contract");
                  _;
                }
                // --- Core methods ---
                /**
                 * @notice Invoked by RoundImplementation on creation to
                 * set the round for which the voting contracts is to be used
                 *
                 */
                function init() external {
                  require(roundAddress == address(0), "init: roundAddress already set");
                  roundAddress = msg.sender;
                }
                /**
                 * @notice Invoked by RoundImplementation to allow voter to case
                 * vote for grants during a round.
                 *
                 * @dev
                 * - allows contributor to do cast multiple votes which could be weighted.
                 * - should be invoked by RoundImplementation contract
                 * - ideally IVotingStrategy implementation should emit events after a vote is cast
                 * - this would be triggered when a voter casts their vote via grant explorer
                 *
                 * @param _encodedVotes encoded votes
                 * @param _voterAddress voter address
                 */
                function vote(bytes[] calldata _encodedVotes, address _voterAddress) external virtual payable;
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)
              pragma solidity ^0.8.0;
              /**
               * @dev Interface of the ERC20 standard as defined in the EIP.
               */
              interface IERC20Upgradeable {
                  /**
                   * @dev Emitted when `value` tokens are moved from one account (`from`) to
                   * another (`to`).
                   *
                   * Note that `value` may be zero.
                   */
                  event Transfer(address indexed from, address indexed to, uint256 value);
                  /**
                   * @dev Emitted when the allowance of a `spender` for an `owner` is set by
                   * a call to {approve}. `value` is the new allowance.
                   */
                  event Approval(address indexed owner, address indexed spender, uint256 value);
                  /**
                   * @dev Returns the amount of tokens in existence.
                   */
                  function totalSupply() external view returns (uint256);
                  /**
                   * @dev Returns the amount of tokens owned by `account`.
                   */
                  function balanceOf(address account) external view returns (uint256);
                  /**
                   * @dev Moves `amount` tokens from the caller's account to `to`.
                   *
                   * Returns a boolean value indicating whether the operation succeeded.
                   *
                   * Emits a {Transfer} event.
                   */
                  function transfer(address to, uint256 amount) external returns (bool);
                  /**
                   * @dev Returns the remaining number of tokens that `spender` will be
                   * allowed to spend on behalf of `owner` through {transferFrom}. This is
                   * zero by default.
                   *
                   * This value changes when {approve} or {transferFrom} are called.
                   */
                  function allowance(address owner, address spender) external view returns (uint256);
                  /**
                   * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
                   *
                   * Returns a boolean value indicating whether the operation succeeded.
                   *
                   * IMPORTANT: Beware that changing an allowance with this method brings the risk
                   * that someone may use both the old and the new allowance by unfortunate
                   * transaction ordering. One possible solution to mitigate this race
                   * condition is to first reduce the spender's allowance to 0 and set the
                   * desired value afterwards:
                   * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
                   *
                   * Emits an {Approval} event.
                   */
                  function approve(address spender, uint256 amount) external returns (bool);
                  /**
                   * @dev Moves `amount` tokens from `from` to `to` using the
                   * allowance mechanism. `amount` is then deducted from the caller's
                   * allowance.
                   *
                   * Returns a boolean value indicating whether the operation succeeded.
                   *
                   * Emits a {Transfer} event.
                   */
                  function transferFrom(
                      address from,
                      address to,
                      uint256 amount
                  ) external returns (bool);
              }
              

              File 3 of 7: GnosisSafeProxy
              // SPDX-License-Identifier: LGPL-3.0-only
              pragma solidity >=0.7.0 <0.9.0;
              
              /// @title IProxy - Helper interface to access masterCopy of the Proxy on-chain
              /// @author Richard Meissner - <richard@gnosis.io>
              interface IProxy {
                  function masterCopy() external view returns (address);
              }
              
              /// @title GnosisSafeProxy - Generic proxy contract allows to execute all transactions applying the code of a master contract.
              /// @author Stefan George - <stefan@gnosis.io>
              /// @author Richard Meissner - <richard@gnosis.io>
              contract GnosisSafeProxy {
                  // singleton always needs to be first declared variable, to ensure that it is at the same location in the contracts to which calls are delegated.
                  // To reduce deployment costs this variable is internal and needs to be retrieved via `getStorageAt`
                  address internal singleton;
              
                  /// @dev Constructor function sets address of singleton contract.
                  /// @param _singleton Singleton address.
                  constructor(address _singleton) {
                      require(_singleton != address(0), "Invalid singleton address provided");
                      singleton = _singleton;
                  }
              
                  /// @dev Fallback function forwards all transactions and returns all received return data.
                  fallback() external payable {
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          let _singleton := and(sload(0), 0xffffffffffffffffffffffffffffffffffffffff)
                          // 0xa619486e == keccak("masterCopy()"). The value is right padded to 32-bytes with 0s
                          if eq(calldataload(0), 0xa619486e00000000000000000000000000000000000000000000000000000000) {
                              mstore(0, _singleton)
                              return(0, 0x20)
                          }
                          calldatacopy(0, 0, calldatasize())
                          let success := delegatecall(gas(), _singleton, 0, calldatasize(), 0, 0)
                          returndatacopy(0, 0, returndatasize())
                          if eq(success, 0) {
                              revert(0, returndatasize())
                          }
                          return(0, returndatasize())
                      }
                  }
              }
              
              /// @title Proxy Factory - Allows to create new proxy contact and execute a message call to the new proxy within one transaction.
              /// @author Stefan George - <stefan@gnosis.pm>
              contract GnosisSafeProxyFactory {
                  event ProxyCreation(GnosisSafeProxy proxy, address singleton);
              
                  /// @dev Allows to create new proxy contact and execute a message call to the new proxy within one transaction.
                  /// @param singleton Address of singleton contract.
                  /// @param data Payload for message call sent to new proxy contract.
                  function createProxy(address singleton, bytes memory data) public returns (GnosisSafeProxy proxy) {
                      proxy = new GnosisSafeProxy(singleton);
                      if (data.length > 0)
                          // solhint-disable-next-line no-inline-assembly
                          assembly {
                              if eq(call(gas(), proxy, 0, add(data, 0x20), mload(data), 0, 0), 0) {
                                  revert(0, 0)
                              }
                          }
                      emit ProxyCreation(proxy, singleton);
                  }
              
                  /// @dev Allows to retrieve the runtime code of a deployed Proxy. This can be used to check that the expected Proxy was deployed.
                  function proxyRuntimeCode() public pure returns (bytes memory) {
                      return type(GnosisSafeProxy).runtimeCode;
                  }
              
                  /// @dev Allows to retrieve the creation code used for the Proxy deployment. With this it is easily possible to calculate predicted address.
                  function proxyCreationCode() public pure returns (bytes memory) {
                      return type(GnosisSafeProxy).creationCode;
                  }
              
                  /// @dev Allows to create new proxy contact using CREATE2 but it doesn't run the initializer.
                  ///      This method is only meant as an utility to be called from other methods
                  /// @param _singleton Address of singleton contract.
                  /// @param initializer Payload for message call sent to new proxy contract.
                  /// @param saltNonce Nonce that will be used to generate the salt to calculate the address of the new proxy contract.
                  function deployProxyWithNonce(
                      address _singleton,
                      bytes memory initializer,
                      uint256 saltNonce
                  ) internal returns (GnosisSafeProxy proxy) {
                      // If the initializer changes the proxy address should change too. Hashing the initializer data is cheaper than just concatinating it
                      bytes32 salt = keccak256(abi.encodePacked(keccak256(initializer), saltNonce));
                      bytes memory deploymentData = abi.encodePacked(type(GnosisSafeProxy).creationCode, uint256(uint160(_singleton)));
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          proxy := create2(0x0, add(0x20, deploymentData), mload(deploymentData), salt)
                      }
                      require(address(proxy) != address(0), "Create2 call failed");
                  }
              
                  /// @dev Allows to create new proxy contact and execute a message call to the new proxy within one transaction.
                  /// @param _singleton Address of singleton contract.
                  /// @param initializer Payload for message call sent to new proxy contract.
                  /// @param saltNonce Nonce that will be used to generate the salt to calculate the address of the new proxy contract.
                  function createProxyWithNonce(
                      address _singleton,
                      bytes memory initializer,
                      uint256 saltNonce
                  ) public returns (GnosisSafeProxy proxy) {
                      proxy = deployProxyWithNonce(_singleton, initializer, saltNonce);
                      if (initializer.length > 0)
                          // solhint-disable-next-line no-inline-assembly
                          assembly {
                              if eq(call(gas(), proxy, 0, add(initializer, 0x20), mload(initializer), 0, 0), 0) {
                                  revert(0, 0)
                              }
                          }
                      emit ProxyCreation(proxy, _singleton);
                  }
              
                  /// @dev Allows to create new proxy contact, execute a message call to the new proxy and call a specified callback within one transaction
                  /// @param _singleton Address of singleton contract.
                  /// @param initializer Payload for message call sent to new proxy contract.
                  /// @param saltNonce Nonce that will be used to generate the salt to calculate the address of the new proxy contract.
                  /// @param callback Callback that will be invoced after the new proxy contract has been successfully deployed and initialized.
                  function createProxyWithCallback(
                      address _singleton,
                      bytes memory initializer,
                      uint256 saltNonce,
                      IProxyCreationCallback callback
                  ) public returns (GnosisSafeProxy proxy) {
                      uint256 saltNonceWithCallback = uint256(keccak256(abi.encodePacked(saltNonce, callback)));
                      proxy = createProxyWithNonce(_singleton, initializer, saltNonceWithCallback);
                      if (address(callback) != address(0)) callback.proxyCreated(proxy, _singleton, initializer, saltNonce);
                  }
              
                  /// @dev Allows to get the address for a new proxy contact created via `createProxyWithNonce`
                  ///      This method is only meant for address calculation purpose when you use an initializer that would revert,
                  ///      therefore the response is returned with a revert. When calling this method set `from` to the address of the proxy factory.
                  /// @param _singleton Address of singleton contract.
                  /// @param initializer Payload for message call sent to new proxy contract.
                  /// @param saltNonce Nonce that will be used to generate the salt to calculate the address of the new proxy contract.
                  function calculateCreateProxyWithNonceAddress(
                      address _singleton,
                      bytes calldata initializer,
                      uint256 saltNonce
                  ) external returns (GnosisSafeProxy proxy) {
                      proxy = deployProxyWithNonce(_singleton, initializer, saltNonce);
                      revert(string(abi.encodePacked(proxy)));
                  }
              }
              
              interface IProxyCreationCallback {
                  function proxyCreated(
                      GnosisSafeProxy proxy,
                      address _singleton,
                      bytes calldata initializer,
                      uint256 saltNonce
                  ) external;
              }

              File 4 of 7: GnosisSafeProxy
              // SPDX-License-Identifier: LGPL-3.0-only
              pragma solidity >=0.7.0 <0.9.0;
              
              /// @title IProxy - Helper interface to access masterCopy of the Proxy on-chain
              /// @author Richard Meissner - <richard@gnosis.io>
              interface IProxy {
                  function masterCopy() external view returns (address);
              }
              
              /// @title GnosisSafeProxy - Generic proxy contract allows to execute all transactions applying the code of a master contract.
              /// @author Stefan George - <stefan@gnosis.io>
              /// @author Richard Meissner - <richard@gnosis.io>
              contract GnosisSafeProxy {
                  // singleton always needs to be first declared variable, to ensure that it is at the same location in the contracts to which calls are delegated.
                  // To reduce deployment costs this variable is internal and needs to be retrieved via `getStorageAt`
                  address internal singleton;
              
                  /// @dev Constructor function sets address of singleton contract.
                  /// @param _singleton Singleton address.
                  constructor(address _singleton) {
                      require(_singleton != address(0), "Invalid singleton address provided");
                      singleton = _singleton;
                  }
              
                  /// @dev Fallback function forwards all transactions and returns all received return data.
                  fallback() external payable {
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          let _singleton := and(sload(0), 0xffffffffffffffffffffffffffffffffffffffff)
                          // 0xa619486e == keccak("masterCopy()"). The value is right padded to 32-bytes with 0s
                          if eq(calldataload(0), 0xa619486e00000000000000000000000000000000000000000000000000000000) {
                              mstore(0, _singleton)
                              return(0, 0x20)
                          }
                          calldatacopy(0, 0, calldatasize())
                          let success := delegatecall(gas(), _singleton, 0, calldatasize(), 0, 0)
                          returndatacopy(0, 0, returndatasize())
                          if eq(success, 0) {
                              revert(0, returndatasize())
                          }
                          return(0, returndatasize())
                      }
                  }
              }
              
              /// @title Proxy Factory - Allows to create new proxy contact and execute a message call to the new proxy within one transaction.
              /// @author Stefan George - <stefan@gnosis.pm>
              contract GnosisSafeProxyFactory {
                  event ProxyCreation(GnosisSafeProxy proxy, address singleton);
              
                  /// @dev Allows to create new proxy contact and execute a message call to the new proxy within one transaction.
                  /// @param singleton Address of singleton contract.
                  /// @param data Payload for message call sent to new proxy contract.
                  function createProxy(address singleton, bytes memory data) public returns (GnosisSafeProxy proxy) {
                      proxy = new GnosisSafeProxy(singleton);
                      if (data.length > 0)
                          // solhint-disable-next-line no-inline-assembly
                          assembly {
                              if eq(call(gas(), proxy, 0, add(data, 0x20), mload(data), 0, 0), 0) {
                                  revert(0, 0)
                              }
                          }
                      emit ProxyCreation(proxy, singleton);
                  }
              
                  /// @dev Allows to retrieve the runtime code of a deployed Proxy. This can be used to check that the expected Proxy was deployed.
                  function proxyRuntimeCode() public pure returns (bytes memory) {
                      return type(GnosisSafeProxy).runtimeCode;
                  }
              
                  /// @dev Allows to retrieve the creation code used for the Proxy deployment. With this it is easily possible to calculate predicted address.
                  function proxyCreationCode() public pure returns (bytes memory) {
                      return type(GnosisSafeProxy).creationCode;
                  }
              
                  /// @dev Allows to create new proxy contact using CREATE2 but it doesn't run the initializer.
                  ///      This method is only meant as an utility to be called from other methods
                  /// @param _singleton Address of singleton contract.
                  /// @param initializer Payload for message call sent to new proxy contract.
                  /// @param saltNonce Nonce that will be used to generate the salt to calculate the address of the new proxy contract.
                  function deployProxyWithNonce(
                      address _singleton,
                      bytes memory initializer,
                      uint256 saltNonce
                  ) internal returns (GnosisSafeProxy proxy) {
                      // If the initializer changes the proxy address should change too. Hashing the initializer data is cheaper than just concatinating it
                      bytes32 salt = keccak256(abi.encodePacked(keccak256(initializer), saltNonce));
                      bytes memory deploymentData = abi.encodePacked(type(GnosisSafeProxy).creationCode, uint256(uint160(_singleton)));
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          proxy := create2(0x0, add(0x20, deploymentData), mload(deploymentData), salt)
                      }
                      require(address(proxy) != address(0), "Create2 call failed");
                  }
              
                  /// @dev Allows to create new proxy contact and execute a message call to the new proxy within one transaction.
                  /// @param _singleton Address of singleton contract.
                  /// @param initializer Payload for message call sent to new proxy contract.
                  /// @param saltNonce Nonce that will be used to generate the salt to calculate the address of the new proxy contract.
                  function createProxyWithNonce(
                      address _singleton,
                      bytes memory initializer,
                      uint256 saltNonce
                  ) public returns (GnosisSafeProxy proxy) {
                      proxy = deployProxyWithNonce(_singleton, initializer, saltNonce);
                      if (initializer.length > 0)
                          // solhint-disable-next-line no-inline-assembly
                          assembly {
                              if eq(call(gas(), proxy, 0, add(initializer, 0x20), mload(initializer), 0, 0), 0) {
                                  revert(0, 0)
                              }
                          }
                      emit ProxyCreation(proxy, _singleton);
                  }
              
                  /// @dev Allows to create new proxy contact, execute a message call to the new proxy and call a specified callback within one transaction
                  /// @param _singleton Address of singleton contract.
                  /// @param initializer Payload for message call sent to new proxy contract.
                  /// @param saltNonce Nonce that will be used to generate the salt to calculate the address of the new proxy contract.
                  /// @param callback Callback that will be invoced after the new proxy contract has been successfully deployed and initialized.
                  function createProxyWithCallback(
                      address _singleton,
                      bytes memory initializer,
                      uint256 saltNonce,
                      IProxyCreationCallback callback
                  ) public returns (GnosisSafeProxy proxy) {
                      uint256 saltNonceWithCallback = uint256(keccak256(abi.encodePacked(saltNonce, callback)));
                      proxy = createProxyWithNonce(_singleton, initializer, saltNonceWithCallback);
                      if (address(callback) != address(0)) callback.proxyCreated(proxy, _singleton, initializer, saltNonce);
                  }
              
                  /// @dev Allows to get the address for a new proxy contact created via `createProxyWithNonce`
                  ///      This method is only meant for address calculation purpose when you use an initializer that would revert,
                  ///      therefore the response is returned with a revert. When calling this method set `from` to the address of the proxy factory.
                  /// @param _singleton Address of singleton contract.
                  /// @param initializer Payload for message call sent to new proxy contract.
                  /// @param saltNonce Nonce that will be used to generate the salt to calculate the address of the new proxy contract.
                  function calculateCreateProxyWithNonceAddress(
                      address _singleton,
                      bytes calldata initializer,
                      uint256 saltNonce
                  ) external returns (GnosisSafeProxy proxy) {
                      proxy = deployProxyWithNonce(_singleton, initializer, saltNonce);
                      revert(string(abi.encodePacked(proxy)));
                  }
              }
              
              interface IProxyCreationCallback {
                  function proxyCreated(
                      GnosisSafeProxy proxy,
                      address _singleton,
                      bytes calldata initializer,
                      uint256 saltNonce
                  ) external;
              }

              File 5 of 7: RoundImplementation
              // SPDX-License-Identifier: AGPL-3.0-only
              pragma solidity 0.8.17;
              import "@openzeppelin/contracts/access/AccessControlEnumerable.sol";
              import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
              import "@openzeppelin/contracts/utils/Address.sol";
              import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
              import "../votingStrategy/IVotingStrategy.sol";
              import "../payoutStrategy/IPayoutStrategy.sol";
              import "../utils/MetaPtr.sol";
              /**
               * @notice Contract deployed per Round which would managed by
               * a group of ROUND_OPERATOR via the RoundFactory
               *
               */
              contract RoundImplementation is AccessControlEnumerable, Initializable {
                // --- Libraries ---
                using Address for address;
                using SafeERC20 for IERC20;
                // --- Roles ---
                /// @notice round operator role
                bytes32 public constant ROUND_OPERATOR_ROLE = keccak256("ROUND_OPERATOR");
                // --- Events ---
                /// @notice Emitted when the round metaPtr is updated
                event RoundMetaPtrUpdated(MetaPtr oldMetaPtr, MetaPtr newMetaPtr);
                /// @notice Emitted when the application form metaPtr is updated
                event ApplicationMetaPtrUpdated(MetaPtr oldMetaPtr, MetaPtr newMetaPtr);
                /// @notice Emitted when application start time is updated
                event ApplicationsStartTimeUpdated(uint256 oldTime, uint256 newTime);
                /// @notice Emitted when application end time is updated
                event ApplicationsEndTimeUpdated(uint256 oldTime, uint256 newTime);
                /// @notice Emitted when a round start time is updated
                event RoundStartTimeUpdated(uint256 oldTime, uint256 newTime);
                /// @notice Emitted when a round end time is updated
                event RoundEndTimeUpdated(uint256 oldTime, uint256 newTime);
                /// @notice Emitted when projects metaPtr is updated
                event ProjectsMetaPtrUpdated(MetaPtr oldMetaPtr, MetaPtr newMetaPtr);
                /// @notice Emitted when a project has applied to the round
                event NewProjectApplication(bytes32 indexed project, MetaPtr applicationMetaPtr);
                // --- Modifier ---
                /// @notice modifier to check if round has not ended.
                modifier roundHasNotEnded() {
                  // slither-disable-next-line timestamp
                  require(block.timestamp <= roundEndTime, "error: round has ended");
                 _;
                }
                // --- Data ---
                /// @notice Voting Strategy Contract Address
                IVotingStrategy public votingStrategy;
                /// @notice Payout Strategy Contract Address
                IPayoutStrategy public payoutStrategy;
                /// @notice Unix timestamp from when round can accept applications
                uint256 public applicationsStartTime;
                /// @notice Unix timestamp from when round stops accepting applications
                uint256 public applicationsEndTime;
                /// @notice Unix timestamp of the start of the round
                uint256 public roundStartTime;
                /// @notice Unix timestamp of the end of the round
                uint256 public roundEndTime;
                /// @notice Token used to payout match amounts at the end of a round
                IERC20 public token;
                /// @notice MetaPtr to the round metadata
                MetaPtr public roundMetaPtr;
                /// @notice MetaPtr to the application form schema
                MetaPtr public applicationMetaPtr;
                /// @notice MetaPtr to the projects
                MetaPtr public projectsMetaPtr;
                // --- Core methods ---
                /**
                 * @notice Instantiates a new round
                 * @param encodedParameters Encoded parameters for program creation
                 * @dev encodedParameters
                 *  - _votingStrategy Deployed voting strategy contract
                 *  - _payoutStrategy Deployed payout strategy contract
                 *  - _applicationsStartTime Unix timestamp from when round can accept applications
                 *  - _applicationsEndTime Unix timestamp from when round stops accepting applications
                 *  - _roundStartTime Unix timestamp of the start of the round
                 *  - _roundEndTime Unix timestamp of the end of the round
                 *  - _token Address of the ERC20 token for accepting matching pool contributions
                 *  - _roundMetaPtr MetaPtr to the round metadata
                 *  - _applicationMetaPtr MetaPtr to the application form schema
                 *  - _adminRoles Addresses to be granted DEFAULT_ADMIN_ROLE
                 *  - _roundOperators Addresses to be granted ROUND_OPERATOR_ROLE
                 */
                function initialize(
                  bytes calldata encodedParameters
                ) external initializer {
                  // Decode _encodedParameters
                  (
                    IVotingStrategy _votingStrategy,
                    IPayoutStrategy _payoutStrategy,
                    uint256 _applicationsStartTime,
                    uint256 _applicationsEndTime,
                    uint256 _roundStartTime,
                    uint256 _roundEndTime,
                    IERC20 _token,
                    MetaPtr memory _roundMetaPtr,
                    MetaPtr memory _applicationMetaPtr,
                    address[] memory _adminRoles,
                    address[] memory _roundOperators
                  ) = abi.decode(
                    encodedParameters, (
                    IVotingStrategy,
                    IPayoutStrategy,
                    uint256,
                    uint256,
                    uint256,
                    uint256,
                    IERC20,
                    MetaPtr,
                    MetaPtr,
                    address[],
                    address[]
                  ));
                  // slither-disable-next-line timestamp
                  require(_applicationsStartTime >= block.timestamp, "initialize: applications start time has already passed");
                  require(_applicationsEndTime > _applicationsStartTime, "initialize: application end time should be after application start time");
                  require(_roundEndTime >= _applicationsEndTime, "initialize: application end time should be before round end time");
                  require(_roundEndTime > _roundStartTime, "initialize: end time should be after start time");
                  require(_roundStartTime >= _applicationsStartTime, "initialize: round start time should be after application start time");
                  votingStrategy = _votingStrategy;
                  payoutStrategy = _payoutStrategy;
                  applicationsStartTime = _applicationsStartTime;
                  applicationsEndTime = _applicationsEndTime;
                  roundStartTime = _roundStartTime;
                  roundEndTime = _roundEndTime;
                  token = _token;
                  // Invoke init on voting contract
                  votingStrategy.init();
                  // Invoke init on payout contract
                  payoutStrategy.init();
                  // Emit RoundMetaPtrUpdated event for indexing
                  emit RoundMetaPtrUpdated(roundMetaPtr, _roundMetaPtr);
                  roundMetaPtr = _roundMetaPtr;
                  // Emit ApplicationMetaPtrUpdated event for indexing
                  emit ApplicationMetaPtrUpdated(applicationMetaPtr, _applicationMetaPtr);
                  applicationMetaPtr = _applicationMetaPtr;
                  // Assigning default admin role
                  for (uint256 i = 0; i < _adminRoles.length; ++i) {
                    _grantRole(DEFAULT_ADMIN_ROLE, _adminRoles[i]);
                  }
                  // Assigning round operators
                  for (uint256 i = 0; i < _roundOperators.length; ++i) {
                    _grantRole(ROUND_OPERATOR_ROLE, _roundOperators[i]);
                  }
                }
                // @notice Update roundMetaPtr (only by ROUND_OPERATOR_ROLE)
                /// @param newRoundMetaPtr new roundMetaPtr
                function updateRoundMetaPtr(MetaPtr memory newRoundMetaPtr) external roundHasNotEnded onlyRole(ROUND_OPERATOR_ROLE) {
                  emit RoundMetaPtrUpdated(roundMetaPtr, newRoundMetaPtr);
                  roundMetaPtr = newRoundMetaPtr;
                }
                // @notice Update applicationMetaPtr (only by ROUND_OPERATOR_ROLE)
                /// @param newApplicationMetaPtr new applicationMetaPtr
                function updateApplicationMetaPtr(MetaPtr memory newApplicationMetaPtr) external roundHasNotEnded onlyRole(ROUND_OPERATOR_ROLE) {
                  emit ApplicationMetaPtrUpdated(applicationMetaPtr, newApplicationMetaPtr);
                  applicationMetaPtr = newApplicationMetaPtr;
                }
                /// @notice Update roundStartTime (only by ROUND_OPERATOR_ROLE)
                /// @param newRoundStartTime new roundStartTime
                function updateRoundStartTime(uint256 newRoundStartTime) external roundHasNotEnded onlyRole(ROUND_OPERATOR_ROLE) {
                  // slither-disable-next-line timestamp
                  require(newRoundStartTime >= block.timestamp, "updateRoundStartTime: start time has already passed");
                  require(newRoundStartTime >= applicationsStartTime, "updateRoundStartTime: start time should be after application start time");
                  require(newRoundStartTime < roundEndTime, "updateRoundStartTime: start time should be before round end time");
                  emit RoundStartTimeUpdated(roundStartTime, newRoundStartTime);
                  roundStartTime = newRoundStartTime;
                }
                /// @notice Update roundEndTime (only by ROUND_OPERATOR_ROLE)
                /// @param newRoundEndTime new roundEndTime
                function updateRoundEndTime(uint256 newRoundEndTime) external roundHasNotEnded onlyRole(ROUND_OPERATOR_ROLE) {
                  // slither-disable-next-line timestamp
                  require(newRoundEndTime >= block.timestamp, "updateRoundEndTime: end time has already passed");
                  require(newRoundEndTime > roundStartTime, "updateRoundEndTime: end time should be after start time");
                  require(newRoundEndTime >= applicationsEndTime, "updateRoundEndTime: end time should be after application end time");
                  emit RoundEndTimeUpdated(roundEndTime, newRoundEndTime);
                  roundEndTime = newRoundEndTime;
                }
                /// @notice Update applicationsStartTime (only by ROUND_OPERATOR_ROLE)
                /// @param newApplicationsStartTime new applicationsStartTime
                function updateApplicationsStartTime(uint256 newApplicationsStartTime) external roundHasNotEnded onlyRole(ROUND_OPERATOR_ROLE) {
                  // slither-disable-next-line timestamp
                  require(newApplicationsStartTime >= block.timestamp, "updateApplicationsStartTime: application start time has already passed");
                  require(newApplicationsStartTime <= roundStartTime, "updateApplicationsStartTime: should be before round start time");
                  require(newApplicationsStartTime < applicationsEndTime, "updateApplicationsStartTime: should be before application end time");
                  emit ApplicationsStartTimeUpdated(applicationsStartTime, newApplicationsStartTime);
                  applicationsStartTime = newApplicationsStartTime;
                }
                /// @notice Update applicationsEndTime (only by ROUND_OPERATOR_ROLE)
                /// @param newApplicationsEndTime new applicationsEndTime
                function updateApplicationsEndTime(uint256 newApplicationsEndTime) external roundHasNotEnded onlyRole(ROUND_OPERATOR_ROLE) {
                  // slither-disable-next-line timestamp
                  require(newApplicationsEndTime >= block.timestamp, "updateApplicationsEndTime: application end time has already passed");
                  require(newApplicationsEndTime > applicationsStartTime, "updateApplicationsEndTime: application end time should be after application start time");
                  require(newApplicationsEndTime <= roundEndTime, "updateApplicationsEndTime: should be before round end time");
                  emit ApplicationsEndTimeUpdated(applicationsEndTime, newApplicationsEndTime);
                  applicationsEndTime = newApplicationsEndTime;
                }
                /// @notice Update projectsMetaPtr (only by ROUND_OPERATOR_ROLE)
                /// @param newProjectsMetaPtr new ProjectsMetaPtr
                function updateProjectsMetaPtr(MetaPtr calldata newProjectsMetaPtr) external roundHasNotEnded onlyRole(ROUND_OPERATOR_ROLE) {
                  emit ProjectsMetaPtrUpdated(projectsMetaPtr, newProjectsMetaPtr);
                  projectsMetaPtr = newProjectsMetaPtr;
                }
                /// @notice Submit a project application
                /// @param projectID unique hash of the project
                /// @param newApplicationMetaPtr appliction metaPtr
                function applyToRound(bytes32 projectID, MetaPtr calldata newApplicationMetaPtr) external {
                  // slither-disable-next-line timestamp
                  require(
                    applicationsStartTime <= block.timestamp  &&
                    block.timestamp <= applicationsEndTime,
                    "applyToRound: round is not accepting application"
                  );
                  emit NewProjectApplication(projectID, newApplicationMetaPtr);
                }
                /// @notice Invoked by voter to cast votes
                /// @param encodedVotes encoded vote
                /// @dev value is to handle native token voting
                function vote(bytes[] memory encodedVotes) external payable {
                  // slither-disable-next-line timestamp
                  require(
                    roundStartTime <= block.timestamp &&
                    block.timestamp <= roundEndTime,
                    "vote: round is not active"
                  );
                  votingStrategy.vote{value: msg.value}(encodedVotes, msg.sender);
                }
                /// @notice Invoked by round operator to update distribution on payout contract
                /// @param encodedDistribution encoded distribution
                function updateDistribution(bytes memory encodedDistribution) external onlyRole(ROUND_OPERATOR_ROLE) {
                  payoutStrategy.updateDistribution(encodedDistribution);
                }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts (last updated v4.5.0) (access/AccessControlEnumerable.sol)
              pragma solidity ^0.8.0;
              import "./IAccessControlEnumerable.sol";
              import "./AccessControl.sol";
              import "../utils/structs/EnumerableSet.sol";
              /**
               * @dev Extension of {AccessControl} that allows enumerating the members of each role.
               */
              abstract contract AccessControlEnumerable is IAccessControlEnumerable, AccessControl {
                  using EnumerableSet for EnumerableSet.AddressSet;
                  mapping(bytes32 => EnumerableSet.AddressSet) private _roleMembers;
                  /**
                   * @dev See {IERC165-supportsInterface}.
                   */
                  function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
                      return interfaceId == type(IAccessControlEnumerable).interfaceId || super.supportsInterface(interfaceId);
                  }
                  /**
                   * @dev Returns one of the accounts that have `role`. `index` must be a
                   * value between 0 and {getRoleMemberCount}, non-inclusive.
                   *
                   * Role bearers are not sorted in any particular way, and their ordering may
                   * change at any point.
                   *
                   * WARNING: When using {getRoleMember} and {getRoleMemberCount}, make sure
                   * you perform all queries on the same block. See the following
                   * https://forum.openzeppelin.com/t/iterating-over-elements-on-enumerableset-in-openzeppelin-contracts/2296[forum post]
                   * for more information.
                   */
                  function getRoleMember(bytes32 role, uint256 index) public view virtual override returns (address) {
                      return _roleMembers[role].at(index);
                  }
                  /**
                   * @dev Returns the number of accounts that have `role`. Can be used
                   * together with {getRoleMember} to enumerate all bearers of a role.
                   */
                  function getRoleMemberCount(bytes32 role) public view virtual override returns (uint256) {
                      return _roleMembers[role].length();
                  }
                  /**
                   * @dev Overload {_grantRole} to track enumerable memberships
                   */
                  function _grantRole(bytes32 role, address account) internal virtual override {
                      super._grantRole(role, account);
                      _roleMembers[role].add(account);
                  }
                  /**
                   * @dev Overload {_revokeRole} to track enumerable memberships
                   */
                  function _revokeRole(bytes32 role, address account) internal virtual override {
                      super._revokeRole(role, account);
                      _roleMembers[role].remove(account);
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)
              pragma solidity ^0.8.0;
              import "../IERC20.sol";
              import "../../../utils/Address.sol";
              /**
               * @title SafeERC20
               * @dev Wrappers around ERC20 operations that throw on failure (when the token
               * contract returns false). Tokens that return no value (and instead revert or
               * throw on failure) are also supported, non-reverting calls are assumed to be
               * successful.
               * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
               * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
               */
              library SafeERC20 {
                  using Address for address;
                  function safeTransfer(
                      IERC20 token,
                      address to,
                      uint256 value
                  ) internal {
                      _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
                  }
                  function safeTransferFrom(
                      IERC20 token,
                      address from,
                      address to,
                      uint256 value
                  ) internal {
                      _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
                  }
                  /**
                   * @dev Deprecated. This function has issues similar to the ones found in
                   * {IERC20-approve}, and its usage is discouraged.
                   *
                   * Whenever possible, use {safeIncreaseAllowance} and
                   * {safeDecreaseAllowance} instead.
                   */
                  function safeApprove(
                      IERC20 token,
                      address spender,
                      uint256 value
                  ) internal {
                      // safeApprove should only be called when setting an initial allowance,
                      // or when resetting it to zero. To increase and decrease it, use
                      // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
                      require(
                          (value == 0) || (token.allowance(address(this), spender) == 0),
                          "SafeERC20: approve from non-zero to non-zero allowance"
                      );
                      _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
                  }
                  function safeIncreaseAllowance(
                      IERC20 token,
                      address spender,
                      uint256 value
                  ) internal {
                      uint256 newAllowance = token.allowance(address(this), spender) + value;
                      _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
                  }
                  function safeDecreaseAllowance(
                      IERC20 token,
                      address spender,
                      uint256 value
                  ) internal {
                      unchecked {
                          uint256 oldAllowance = token.allowance(address(this), spender);
                          require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
                          uint256 newAllowance = oldAllowance - value;
                          _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
                      }
                  }
                  /**
                   * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
                   * on the return value: the return value is optional (but if data is returned, it must not be false).
                   * @param token The token targeted by the call.
                   * @param data The call data (encoded using abi.encode or one of its variants).
                   */
                  function _callOptionalReturn(IERC20 token, bytes memory data) private {
                      // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
                      // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
                      // the target address contains contract code and also asserts for success in the low-level call.
                      bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
                      if (returndata.length > 0) {
                          // Return data is optional
                          require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
                      }
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)
              pragma solidity ^0.8.1;
              /**
               * @dev Collection of functions related to the address type
               */
              library Address {
                  /**
                   * @dev Returns true if `account` is a contract.
                   *
                   * [IMPORTANT]
                   * ====
                   * It is unsafe to assume that an address for which this function returns
                   * false is an externally-owned account (EOA) and not a contract.
                   *
                   * Among others, `isContract` will return false for the following
                   * types of addresses:
                   *
                   *  - an externally-owned account
                   *  - a contract in construction
                   *  - an address where a contract will be created
                   *  - an address where a contract lived, but was destroyed
                   * ====
                   *
                   * [IMPORTANT]
                   * ====
                   * You shouldn't rely on `isContract` to protect against flash loan attacks!
                   *
                   * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
                   * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
                   * constructor.
                   * ====
                   */
                  function isContract(address account) internal view returns (bool) {
                      // This method relies on extcodesize/address.code.length, which returns 0
                      // for contracts in construction, since the code is only stored at the end
                      // of the constructor execution.
                      return account.code.length > 0;
                  }
                  /**
                   * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
                   * `recipient`, forwarding all available gas and reverting on errors.
                   *
                   * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
                   * of certain opcodes, possibly making contracts go over the 2300 gas limit
                   * imposed by `transfer`, making them unable to receive funds via
                   * `transfer`. {sendValue} removes this limitation.
                   *
                   * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
                   *
                   * IMPORTANT: because control is transferred to `recipient`, care must be
                   * taken to not create reentrancy vulnerabilities. Consider using
                   * {ReentrancyGuard} or the
                   * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
                   */
                  function sendValue(address payable recipient, uint256 amount) internal {
                      require(address(this).balance >= amount, "Address: insufficient balance");
                      (bool success, ) = recipient.call{value: amount}("");
                      require(success, "Address: unable to send value, recipient may have reverted");
                  }
                  /**
                   * @dev Performs a Solidity function call using a low level `call`. A
                   * plain `call` is an unsafe replacement for a function call: use this
                   * function instead.
                   *
                   * If `target` reverts with a revert reason, it is bubbled up by this
                   * function (like regular Solidity function calls).
                   *
                   * Returns the raw returned data. To convert to the expected return value,
                   * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
                   *
                   * Requirements:
                   *
                   * - `target` must be a contract.
                   * - calling `target` with `data` must not revert.
                   *
                   * _Available since v3.1._
                   */
                  function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                      return functionCall(target, data, "Address: low-level call failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
                   * `errorMessage` as a fallback revert reason when `target` reverts.
                   *
                   * _Available since v3.1._
                   */
                  function functionCall(
                      address target,
                      bytes memory data,
                      string memory errorMessage
                  ) internal returns (bytes memory) {
                      return functionCallWithValue(target, data, 0, errorMessage);
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                   * but also transferring `value` wei to `target`.
                   *
                   * Requirements:
                   *
                   * - the calling contract must have an ETH balance of at least `value`.
                   * - the called Solidity function must be `payable`.
                   *
                   * _Available since v3.1._
                   */
                  function functionCallWithValue(
                      address target,
                      bytes memory data,
                      uint256 value
                  ) internal returns (bytes memory) {
                      return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
                   * with `errorMessage` as a fallback revert reason when `target` reverts.
                   *
                   * _Available since v3.1._
                   */
                  function functionCallWithValue(
                      address target,
                      bytes memory data,
                      uint256 value,
                      string memory errorMessage
                  ) internal returns (bytes memory) {
                      require(address(this).balance >= value, "Address: insufficient balance for call");
                      require(isContract(target), "Address: call to non-contract");
                      (bool success, bytes memory returndata) = target.call{value: value}(data);
                      return verifyCallResult(success, returndata, errorMessage);
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                   * but performing a static call.
                   *
                   * _Available since v3.3._
                   */
                  function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                      return functionStaticCall(target, data, "Address: low-level static call failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                   * but performing a static call.
                   *
                   * _Available since v3.3._
                   */
                  function functionStaticCall(
                      address target,
                      bytes memory data,
                      string memory errorMessage
                  ) internal view returns (bytes memory) {
                      require(isContract(target), "Address: static call to non-contract");
                      (bool success, bytes memory returndata) = target.staticcall(data);
                      return verifyCallResult(success, returndata, errorMessage);
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                   * but performing a delegate call.
                   *
                   * _Available since v3.4._
                   */
                  function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
                      return functionDelegateCall(target, data, "Address: low-level delegate call failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                   * but performing a delegate call.
                   *
                   * _Available since v3.4._
                   */
                  function functionDelegateCall(
                      address target,
                      bytes memory data,
                      string memory errorMessage
                  ) internal returns (bytes memory) {
                      require(isContract(target), "Address: delegate call to non-contract");
                      (bool success, bytes memory returndata) = target.delegatecall(data);
                      return verifyCallResult(success, returndata, errorMessage);
                  }
                  /**
                   * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
                   * revert reason using the provided one.
                   *
                   * _Available since v4.3._
                   */
                  function verifyCallResult(
                      bool success,
                      bytes memory returndata,
                      string memory errorMessage
                  ) internal pure returns (bytes memory) {
                      if (success) {
                          return returndata;
                      } else {
                          // Look for revert reason and bubble it up if present
                          if (returndata.length > 0) {
                              // The easiest way to bubble the revert reason is using memory via assembly
                              assembly {
                                  let returndata_size := mload(returndata)
                                  revert(add(32, returndata), returndata_size)
                              }
                          } else {
                              revert(errorMessage);
                          }
                      }
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts (last updated v4.6.0) (proxy/utils/Initializable.sol)
              pragma solidity ^0.8.2;
              import "../../utils/AddressUpgradeable.sol";
              /**
               * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
               * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an
               * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
               * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
               *
               * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be
               * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in
               * case an upgrade adds a module that needs to be initialized.
               *
               * For example:
               *
               * [.hljs-theme-light.nopadding]
               * ```
               * contract MyToken is ERC20Upgradeable {
               *     function initialize() initializer public {
               *         __ERC20_init("MyToken", "MTK");
               *     }
               * }
               * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {
               *     function initializeV2() reinitializer(2) public {
               *         __ERC20Permit_init("MyToken");
               *     }
               * }
               * ```
               *
               * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
               * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
               *
               * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
               * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
               *
               * [CAUTION]
               * ====
               * Avoid leaving a contract uninitialized.
               *
               * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
               * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke
               * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:
               *
               * [.hljs-theme-light.nopadding]
               * ```
               * /// @custom:oz-upgrades-unsafe-allow constructor
               * constructor() {
               *     _disableInitializers();
               * }
               * ```
               * ====
               */
              abstract contract Initializable {
                  /**
                   * @dev Indicates that the contract has been initialized.
                   * @custom:oz-retyped-from bool
                   */
                  uint8 private _initialized;
                  /**
                   * @dev Indicates that the contract is in the process of being initialized.
                   */
                  bool private _initializing;
                  /**
                   * @dev Triggered when the contract has been initialized or reinitialized.
                   */
                  event Initialized(uint8 version);
                  /**
                   * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
                   * `onlyInitializing` functions can be used to initialize parent contracts. Equivalent to `reinitializer(1)`.
                   */
                  modifier initializer() {
                      bool isTopLevelCall = _setInitializedVersion(1);
                      if (isTopLevelCall) {
                          _initializing = true;
                      }
                      _;
                      if (isTopLevelCall) {
                          _initializing = false;
                          emit Initialized(1);
                      }
                  }
                  /**
                   * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
                   * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
                   * used to initialize parent contracts.
                   *
                   * `initializer` is equivalent to `reinitializer(1)`, so a reinitializer may be used after the original
                   * initialization step. This is essential to configure modules that are added through upgrades and that require
                   * initialization.
                   *
                   * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
                   * a contract, executing them in the right order is up to the developer or operator.
                   */
                  modifier reinitializer(uint8 version) {
                      bool isTopLevelCall = _setInitializedVersion(version);
                      if (isTopLevelCall) {
                          _initializing = true;
                      }
                      _;
                      if (isTopLevelCall) {
                          _initializing = false;
                          emit Initialized(version);
                      }
                  }
                  /**
                   * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
                   * {initializer} and {reinitializer} modifiers, directly or indirectly.
                   */
                  modifier onlyInitializing() {
                      require(_initializing, "Initializable: contract is not initializing");
                      _;
                  }
                  /**
                   * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.
                   * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized
                   * to any version. It is recommended to use this to lock implementation contracts that are designed to be called
                   * through proxies.
                   */
                  function _disableInitializers() internal virtual {
                      _setInitializedVersion(type(uint8).max);
                  }
                  function _setInitializedVersion(uint8 version) private returns (bool) {
                      // If the contract is initializing we ignore whether _initialized is set in order to support multiple
                      // inheritance patterns, but we only do this in the context of a constructor, and for the lowest level
                      // of initializers, because in other contexts the contract may have been reentered.
                      if (_initializing) {
                          require(
                              version == 1 && !AddressUpgradeable.isContract(address(this)),
                              "Initializable: contract is already initialized"
                          );
                          return false;
                      } else {
                          require(_initialized < version, "Initializable: contract is already initialized");
                          _initialized = version;
                          return true;
                      }
                  }
              }
              // SPDX-License-Identifier: AGPL-3.0-only
              pragma solidity 0.8.17;
              /**
               * @notice Defines the abstract contract for voting algorithms on grants
               * within a round. Any new voting algorithm would be expected to
               * extend this abstract contract.
               * Every IVotingStrategy contract would be unique to RoundImplementation
               * and would be deployed before creating a round
               */
              abstract contract IVotingStrategy {
                 // --- Data ---
                /// @notice Round address
                address public roundAddress;
                // --- Modifier ---
                /// @notice modifier to check if sender is round contract.
                modifier isRoundContract() {
                  require(roundAddress != address(0), "error: voting contract not linked to a round");
                  require(msg.sender == roundAddress, "error: can be invoked only by round contract");
                  _;
                }
                // --- Core methods ---
                /**
                 * @notice Invoked by RoundImplementation on creation to
                 * set the round for which the voting contracts is to be used
                 *
                 */
                function init() external {
                  require(roundAddress == address(0), "init: roundAddress already set");
                  roundAddress = msg.sender;
                }
                /**
                 * @notice Invoked by RoundImplementation to allow voter to case
                 * vote for grants during a round.
                 *
                 * @dev
                 * - allows contributor to do cast multiple votes which could be weighted.
                 * - should be invoked by RoundImplementation contract
                 * - ideally IVotingStrategy implementation should emit events after a vote is cast
                 * - this would be triggered when a voter casts their vote via grant explorer
                 *
                 * @param _encodedVotes encoded votes
                 * @param _voterAddress voter address
                 */
                function vote(bytes[] calldata _encodedVotes, address _voterAddress) external virtual payable;
              }
              // SPDX-License-Identifier: AGPL-3.0-only
              pragma solidity 0.8.17;
              /**
               * @notice Defines the abstract contract for payout strategies
               * for a round. Any new payout strategy would be expected to
               * extend this abstract contract.
               * Every IPayoutStrategy contract would be unique to RoundImplementation
               * and would be deployed before creating a round 
               *
               * @dev
               *  - Deployed before creating a round
               *  - init will be invoked during round creation to link the payout
               *    strategy to the round contract 
               *  - TODO: add function distribute() to actually distribute the funds  
               */
              abstract contract IPayoutStrategy {
                 // --- Data ---
                /// @notice Round address
                address public roundAddress;
                // --- Modifier ---
                /// @notice modifier to check if sender is round contract.
                modifier isRoundContract() {
                  require(roundAddress != address(0), "error: payout contract not linked to a round");
                  require(msg.sender == roundAddress, "error: can be invoked only by round contract");
                  _;
                }
                // --- Core methods ---
                /**
                 * @notice Invoked by RoundImplementation on creation to
                 * set the round for which the payout strategy is to be used
                 *
                 */
                function init() external {
                  require(roundAddress == address(0), "init: roundAddress already set");
                  roundAddress = msg.sender;
                }
                /**
                 * @notice Invoked by RoundImplementation to upload distribution to the
                 * payout strategy
                 *
                 * @dev
                 * - should be invoked by RoundImplementation contract
                 * - ideally IPayoutStrategy implementation should emit events after 
                 *   distribution is updated
                 * - would be invoked at the end of the round
                 *
                 * @param _encodedDistribution encoded distribution
                 */
                function updateDistribution(bytes calldata _encodedDistribution) external virtual;
              }
              // SPDX-License-Identifier: AGPL-3.0-only
              pragma solidity 0.8.17;
              struct MetaPtr {
                /// @notice Protocol ID corresponding to a specific protocol.
                /// More info at https://github.com/gitcoinco/grants-round/tree/main/packages/contracts/docs/MetaPtrProtocol.md
                uint256 protocol;
                
                /// @notice Pointer to fetch metadata for the specified protocol
                string pointer;
              }// SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts v4.4.1 (access/IAccessControlEnumerable.sol)
              pragma solidity ^0.8.0;
              import "./IAccessControl.sol";
              /**
               * @dev External interface of AccessControlEnumerable declared to support ERC165 detection.
               */
              interface IAccessControlEnumerable is IAccessControl {
                  /**
                   * @dev Returns one of the accounts that have `role`. `index` must be a
                   * value between 0 and {getRoleMemberCount}, non-inclusive.
                   *
                   * Role bearers are not sorted in any particular way, and their ordering may
                   * change at any point.
                   *
                   * WARNING: When using {getRoleMember} and {getRoleMemberCount}, make sure
                   * you perform all queries on the same block. See the following
                   * https://forum.openzeppelin.com/t/iterating-over-elements-on-enumerableset-in-openzeppelin-contracts/2296[forum post]
                   * for more information.
                   */
                  function getRoleMember(bytes32 role, uint256 index) external view returns (address);
                  /**
                   * @dev Returns the number of accounts that have `role`. Can be used
                   * together with {getRoleMember} to enumerate all bearers of a role.
                   */
                  function getRoleMemberCount(bytes32 role) external view returns (uint256);
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts (last updated v4.6.0) (access/AccessControl.sol)
              pragma solidity ^0.8.0;
              import "./IAccessControl.sol";
              import "../utils/Context.sol";
              import "../utils/Strings.sol";
              import "../utils/introspection/ERC165.sol";
              /**
               * @dev Contract module that allows children to implement role-based access
               * control mechanisms. This is a lightweight version that doesn't allow enumerating role
               * members except through off-chain means by accessing the contract event logs. Some
               * applications may benefit from on-chain enumerability, for those cases see
               * {AccessControlEnumerable}.
               *
               * Roles are referred to by their `bytes32` identifier. These should be exposed
               * in the external API and be unique. The best way to achieve this is by
               * using `public constant` hash digests:
               *
               * ```
               * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
               * ```
               *
               * Roles can be used to represent a set of permissions. To restrict access to a
               * function call, use {hasRole}:
               *
               * ```
               * function foo() public {
               *     require(hasRole(MY_ROLE, msg.sender));
               *     ...
               * }
               * ```
               *
               * Roles can be granted and revoked dynamically via the {grantRole} and
               * {revokeRole} functions. Each role has an associated admin role, and only
               * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
               *
               * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
               * that only accounts with this role will be able to grant or revoke other
               * roles. More complex role relationships can be created by using
               * {_setRoleAdmin}.
               *
               * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
               * grant and revoke this role. Extra precautions should be taken to secure
               * accounts that have been granted it.
               */
              abstract contract AccessControl is Context, IAccessControl, ERC165 {
                  struct RoleData {
                      mapping(address => bool) members;
                      bytes32 adminRole;
                  }
                  mapping(bytes32 => RoleData) private _roles;
                  bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;
                  /**
                   * @dev Modifier that checks that an account has a specific role. Reverts
                   * with a standardized message including the required role.
                   *
                   * The format of the revert reason is given by the following regular expression:
                   *
                   *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
                   *
                   * _Available since v4.1._
                   */
                  modifier onlyRole(bytes32 role) {
                      _checkRole(role);
                      _;
                  }
                  /**
                   * @dev See {IERC165-supportsInterface}.
                   */
                  function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
                      return interfaceId == type(IAccessControl).interfaceId || super.supportsInterface(interfaceId);
                  }
                  /**
                   * @dev Returns `true` if `account` has been granted `role`.
                   */
                  function hasRole(bytes32 role, address account) public view virtual override returns (bool) {
                      return _roles[role].members[account];
                  }
                  /**
                   * @dev Revert with a standard message if `_msgSender()` is missing `role`.
                   * Overriding this function changes the behavior of the {onlyRole} modifier.
                   *
                   * Format of the revert message is described in {_checkRole}.
                   *
                   * _Available since v4.6._
                   */
                  function _checkRole(bytes32 role) internal view virtual {
                      _checkRole(role, _msgSender());
                  }
                  /**
                   * @dev Revert with a standard message if `account` is missing `role`.
                   *
                   * The format of the revert reason is given by the following regular expression:
                   *
                   *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
                   */
                  function _checkRole(bytes32 role, address account) internal view virtual {
                      if (!hasRole(role, account)) {
                          revert(
                              string(
                                  abi.encodePacked(
                                      "AccessControl: account ",
                                      Strings.toHexString(uint160(account), 20),
                                      " is missing role ",
                                      Strings.toHexString(uint256(role), 32)
                                  )
                              )
                          );
                      }
                  }
                  /**
                   * @dev Returns the admin role that controls `role`. See {grantRole} and
                   * {revokeRole}.
                   *
                   * To change a role's admin, use {_setRoleAdmin}.
                   */
                  function getRoleAdmin(bytes32 role) public view virtual override returns (bytes32) {
                      return _roles[role].adminRole;
                  }
                  /**
                   * @dev Grants `role` to `account`.
                   *
                   * If `account` had not been already granted `role`, emits a {RoleGranted}
                   * event.
                   *
                   * Requirements:
                   *
                   * - the caller must have ``role``'s admin role.
                   */
                  function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
                      _grantRole(role, account);
                  }
                  /**
                   * @dev Revokes `role` from `account`.
                   *
                   * If `account` had been granted `role`, emits a {RoleRevoked} event.
                   *
                   * Requirements:
                   *
                   * - the caller must have ``role``'s admin role.
                   */
                  function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
                      _revokeRole(role, account);
                  }
                  /**
                   * @dev Revokes `role` from the calling account.
                   *
                   * Roles are often managed via {grantRole} and {revokeRole}: this function's
                   * purpose is to provide a mechanism for accounts to lose their privileges
                   * if they are compromised (such as when a trusted device is misplaced).
                   *
                   * If the calling account had been revoked `role`, emits a {RoleRevoked}
                   * event.
                   *
                   * Requirements:
                   *
                   * - the caller must be `account`.
                   */
                  function renounceRole(bytes32 role, address account) public virtual override {
                      require(account == _msgSender(), "AccessControl: can only renounce roles for self");
                      _revokeRole(role, account);
                  }
                  /**
                   * @dev Grants `role` to `account`.
                   *
                   * If `account` had not been already granted `role`, emits a {RoleGranted}
                   * event. Note that unlike {grantRole}, this function doesn't perform any
                   * checks on the calling account.
                   *
                   * [WARNING]
                   * ====
                   * This function should only be called from the constructor when setting
                   * up the initial roles for the system.
                   *
                   * Using this function in any other way is effectively circumventing the admin
                   * system imposed by {AccessControl}.
                   * ====
                   *
                   * NOTE: This function is deprecated in favor of {_grantRole}.
                   */
                  function _setupRole(bytes32 role, address account) internal virtual {
                      _grantRole(role, account);
                  }
                  /**
                   * @dev Sets `adminRole` as ``role``'s admin role.
                   *
                   * Emits a {RoleAdminChanged} event.
                   */
                  function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
                      bytes32 previousAdminRole = getRoleAdmin(role);
                      _roles[role].adminRole = adminRole;
                      emit RoleAdminChanged(role, previousAdminRole, adminRole);
                  }
                  /**
                   * @dev Grants `role` to `account`.
                   *
                   * Internal function without access restriction.
                   */
                  function _grantRole(bytes32 role, address account) internal virtual {
                      if (!hasRole(role, account)) {
                          _roles[role].members[account] = true;
                          emit RoleGranted(role, account, _msgSender());
                      }
                  }
                  /**
                   * @dev Revokes `role` from `account`.
                   *
                   * Internal function without access restriction.
                   */
                  function _revokeRole(bytes32 role, address account) internal virtual {
                      if (hasRole(role, account)) {
                          _roles[role].members[account] = false;
                          emit RoleRevoked(role, account, _msgSender());
                      }
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts (last updated v4.6.0) (utils/structs/EnumerableSet.sol)
              pragma solidity ^0.8.0;
              /**
               * @dev Library for managing
               * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
               * types.
               *
               * Sets have the following properties:
               *
               * - Elements are added, removed, and checked for existence in constant time
               * (O(1)).
               * - Elements are enumerated in O(n). No guarantees are made on the ordering.
               *
               * ```
               * contract Example {
               *     // Add the library methods
               *     using EnumerableSet for EnumerableSet.AddressSet;
               *
               *     // Declare a set state variable
               *     EnumerableSet.AddressSet private mySet;
               * }
               * ```
               *
               * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
               * and `uint256` (`UintSet`) are supported.
               */
              library EnumerableSet {
                  // To implement this library for multiple types with as little code
                  // repetition as possible, we write it in terms of a generic Set type with
                  // bytes32 values.
                  // The Set implementation uses private functions, and user-facing
                  // implementations (such as AddressSet) are just wrappers around the
                  // underlying Set.
                  // This means that we can only create new EnumerableSets for types that fit
                  // in bytes32.
                  struct Set {
                      // Storage of set values
                      bytes32[] _values;
                      // Position of the value in the `values` array, plus 1 because index 0
                      // means a value is not in the set.
                      mapping(bytes32 => uint256) _indexes;
                  }
                  /**
                   * @dev Add a value to a set. O(1).
                   *
                   * Returns true if the value was added to the set, that is if it was not
                   * already present.
                   */
                  function _add(Set storage set, bytes32 value) private returns (bool) {
                      if (!_contains(set, value)) {
                          set._values.push(value);
                          // The value is stored at length-1, but we add 1 to all indexes
                          // and use 0 as a sentinel value
                          set._indexes[value] = set._values.length;
                          return true;
                      } else {
                          return false;
                      }
                  }
                  /**
                   * @dev Removes a value from a set. O(1).
                   *
                   * Returns true if the value was removed from the set, that is if it was
                   * present.
                   */
                  function _remove(Set storage set, bytes32 value) private returns (bool) {
                      // We read and store the value's index to prevent multiple reads from the same storage slot
                      uint256 valueIndex = set._indexes[value];
                      if (valueIndex != 0) {
                          // Equivalent to contains(set, value)
                          // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
                          // the array, and then remove the last element (sometimes called as 'swap and pop').
                          // This modifies the order of the array, as noted in {at}.
                          uint256 toDeleteIndex = valueIndex - 1;
                          uint256 lastIndex = set._values.length - 1;
                          if (lastIndex != toDeleteIndex) {
                              bytes32 lastValue = set._values[lastIndex];
                              // Move the last value to the index where the value to delete is
                              set._values[toDeleteIndex] = lastValue;
                              // Update the index for the moved value
                              set._indexes[lastValue] = valueIndex; // Replace lastValue's index to valueIndex
                          }
                          // Delete the slot where the moved value was stored
                          set._values.pop();
                          // Delete the index for the deleted slot
                          delete set._indexes[value];
                          return true;
                      } else {
                          return false;
                      }
                  }
                  /**
                   * @dev Returns true if the value is in the set. O(1).
                   */
                  function _contains(Set storage set, bytes32 value) private view returns (bool) {
                      return set._indexes[value] != 0;
                  }
                  /**
                   * @dev Returns the number of values on the set. O(1).
                   */
                  function _length(Set storage set) private view returns (uint256) {
                      return set._values.length;
                  }
                  /**
                   * @dev Returns the value stored at position `index` in the set. O(1).
                   *
                   * Note that there are no guarantees on the ordering of values inside the
                   * array, and it may change when more values are added or removed.
                   *
                   * Requirements:
                   *
                   * - `index` must be strictly less than {length}.
                   */
                  function _at(Set storage set, uint256 index) private view returns (bytes32) {
                      return set._values[index];
                  }
                  /**
                   * @dev Return the entire set in an array
                   *
                   * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
                   * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
                   * this function has an unbounded cost, and using it as part of a state-changing function may render the function
                   * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
                   */
                  function _values(Set storage set) private view returns (bytes32[] memory) {
                      return set._values;
                  }
                  // Bytes32Set
                  struct Bytes32Set {
                      Set _inner;
                  }
                  /**
                   * @dev Add a value to a set. O(1).
                   *
                   * Returns true if the value was added to the set, that is if it was not
                   * already present.
                   */
                  function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
                      return _add(set._inner, value);
                  }
                  /**
                   * @dev Removes a value from a set. O(1).
                   *
                   * Returns true if the value was removed from the set, that is if it was
                   * present.
                   */
                  function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
                      return _remove(set._inner, value);
                  }
                  /**
                   * @dev Returns true if the value is in the set. O(1).
                   */
                  function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
                      return _contains(set._inner, value);
                  }
                  /**
                   * @dev Returns the number of values in the set. O(1).
                   */
                  function length(Bytes32Set storage set) internal view returns (uint256) {
                      return _length(set._inner);
                  }
                  /**
                   * @dev Returns the value stored at position `index` in the set. O(1).
                   *
                   * Note that there are no guarantees on the ordering of values inside the
                   * array, and it may change when more values are added or removed.
                   *
                   * Requirements:
                   *
                   * - `index` must be strictly less than {length}.
                   */
                  function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
                      return _at(set._inner, index);
                  }
                  /**
                   * @dev Return the entire set in an array
                   *
                   * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
                   * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
                   * this function has an unbounded cost, and using it as part of a state-changing function may render the function
                   * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
                   */
                  function values(Bytes32Set storage set) internal view returns (bytes32[] memory) {
                      return _values(set._inner);
                  }
                  // AddressSet
                  struct AddressSet {
                      Set _inner;
                  }
                  /**
                   * @dev Add a value to a set. O(1).
                   *
                   * Returns true if the value was added to the set, that is if it was not
                   * already present.
                   */
                  function add(AddressSet storage set, address value) internal returns (bool) {
                      return _add(set._inner, bytes32(uint256(uint160(value))));
                  }
                  /**
                   * @dev Removes a value from a set. O(1).
                   *
                   * Returns true if the value was removed from the set, that is if it was
                   * present.
                   */
                  function remove(AddressSet storage set, address value) internal returns (bool) {
                      return _remove(set._inner, bytes32(uint256(uint160(value))));
                  }
                  /**
                   * @dev Returns true if the value is in the set. O(1).
                   */
                  function contains(AddressSet storage set, address value) internal view returns (bool) {
                      return _contains(set._inner, bytes32(uint256(uint160(value))));
                  }
                  /**
                   * @dev Returns the number of values in the set. O(1).
                   */
                  function length(AddressSet storage set) internal view returns (uint256) {
                      return _length(set._inner);
                  }
                  /**
                   * @dev Returns the value stored at position `index` in the set. O(1).
                   *
                   * Note that there are no guarantees on the ordering of values inside the
                   * array, and it may change when more values are added or removed.
                   *
                   * Requirements:
                   *
                   * - `index` must be strictly less than {length}.
                   */
                  function at(AddressSet storage set, uint256 index) internal view returns (address) {
                      return address(uint160(uint256(_at(set._inner, index))));
                  }
                  /**
                   * @dev Return the entire set in an array
                   *
                   * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
                   * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
                   * this function has an unbounded cost, and using it as part of a state-changing function may render the function
                   * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
                   */
                  function values(AddressSet storage set) internal view returns (address[] memory) {
                      bytes32[] memory store = _values(set._inner);
                      address[] memory result;
                      assembly {
                          result := store
                      }
                      return result;
                  }
                  // UintSet
                  struct UintSet {
                      Set _inner;
                  }
                  /**
                   * @dev Add a value to a set. O(1).
                   *
                   * Returns true if the value was added to the set, that is if it was not
                   * already present.
                   */
                  function add(UintSet storage set, uint256 value) internal returns (bool) {
                      return _add(set._inner, bytes32(value));
                  }
                  /**
                   * @dev Removes a value from a set. O(1).
                   *
                   * Returns true if the value was removed from the set, that is if it was
                   * present.
                   */
                  function remove(UintSet storage set, uint256 value) internal returns (bool) {
                      return _remove(set._inner, bytes32(value));
                  }
                  /**
                   * @dev Returns true if the value is in the set. O(1).
                   */
                  function contains(UintSet storage set, uint256 value) internal view returns (bool) {
                      return _contains(set._inner, bytes32(value));
                  }
                  /**
                   * @dev Returns the number of values on the set. O(1).
                   */
                  function length(UintSet storage set) internal view returns (uint256) {
                      return _length(set._inner);
                  }
                  /**
                   * @dev Returns the value stored at position `index` in the set. O(1).
                   *
                   * Note that there are no guarantees on the ordering of values inside the
                   * array, and it may change when more values are added or removed.
                   *
                   * Requirements:
                   *
                   * - `index` must be strictly less than {length}.
                   */
                  function at(UintSet storage set, uint256 index) internal view returns (uint256) {
                      return uint256(_at(set._inner, index));
                  }
                  /**
                   * @dev Return the entire set in an array
                   *
                   * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
                   * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
                   * this function has an unbounded cost, and using it as part of a state-changing function may render the function
                   * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
                   */
                  function values(UintSet storage set) internal view returns (uint256[] memory) {
                      bytes32[] memory store = _values(set._inner);
                      uint256[] memory result;
                      assembly {
                          result := store
                      }
                      return result;
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts v4.4.1 (access/IAccessControl.sol)
              pragma solidity ^0.8.0;
              /**
               * @dev External interface of AccessControl declared to support ERC165 detection.
               */
              interface IAccessControl {
                  /**
                   * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
                   *
                   * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
                   * {RoleAdminChanged} not being emitted signaling this.
                   *
                   * _Available since v3.1._
                   */
                  event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);
                  /**
                   * @dev Emitted when `account` is granted `role`.
                   *
                   * `sender` is the account that originated the contract call, an admin role
                   * bearer except when using {AccessControl-_setupRole}.
                   */
                  event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);
                  /**
                   * @dev Emitted when `account` is revoked `role`.
                   *
                   * `sender` is the account that originated the contract call:
                   *   - if using `revokeRole`, it is the admin role bearer
                   *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
                   */
                  event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);
                  /**
                   * @dev Returns `true` if `account` has been granted `role`.
                   */
                  function hasRole(bytes32 role, address account) external view returns (bool);
                  /**
                   * @dev Returns the admin role that controls `role`. See {grantRole} and
                   * {revokeRole}.
                   *
                   * To change a role's admin, use {AccessControl-_setRoleAdmin}.
                   */
                  function getRoleAdmin(bytes32 role) external view returns (bytes32);
                  /**
                   * @dev Grants `role` to `account`.
                   *
                   * If `account` had not been already granted `role`, emits a {RoleGranted}
                   * event.
                   *
                   * Requirements:
                   *
                   * - the caller must have ``role``'s admin role.
                   */
                  function grantRole(bytes32 role, address account) external;
                  /**
                   * @dev Revokes `role` from `account`.
                   *
                   * If `account` had been granted `role`, emits a {RoleRevoked} event.
                   *
                   * Requirements:
                   *
                   * - the caller must have ``role``'s admin role.
                   */
                  function revokeRole(bytes32 role, address account) external;
                  /**
                   * @dev Revokes `role` from the calling account.
                   *
                   * Roles are often managed via {grantRole} and {revokeRole}: this function's
                   * purpose is to provide a mechanism for accounts to lose their privileges
                   * if they are compromised (such as when a trusted device is misplaced).
                   *
                   * If the calling account had been granted `role`, emits a {RoleRevoked}
                   * event.
                   *
                   * Requirements:
                   *
                   * - the caller must be `account`.
                   */
                  function renounceRole(bytes32 role, address account) external;
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
              pragma solidity ^0.8.0;
              /**
               * @dev Provides information about the current execution context, including the
               * sender of the transaction and its data. While these are generally available
               * via msg.sender and msg.data, they should not be accessed in such a direct
               * manner, since when dealing with meta-transactions the account sending and
               * paying for execution may not be the actual sender (as far as an application
               * is concerned).
               *
               * This contract is only required for intermediate, library-like contracts.
               */
              abstract contract Context {
                  function _msgSender() internal view virtual returns (address) {
                      return msg.sender;
                  }
                  function _msgData() internal view virtual returns (bytes calldata) {
                      return msg.data;
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)
              pragma solidity ^0.8.0;
              /**
               * @dev String operations.
               */
              library Strings {
                  bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
                  /**
                   * @dev Converts a `uint256` to its ASCII `string` decimal representation.
                   */
                  function toString(uint256 value) internal pure returns (string memory) {
                      // Inspired by OraclizeAPI's implementation - MIT licence
                      // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
                      if (value == 0) {
                          return "0";
                      }
                      uint256 temp = value;
                      uint256 digits;
                      while (temp != 0) {
                          digits++;
                          temp /= 10;
                      }
                      bytes memory buffer = new bytes(digits);
                      while (value != 0) {
                          digits -= 1;
                          buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
                          value /= 10;
                      }
                      return string(buffer);
                  }
                  /**
                   * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
                   */
                  function toHexString(uint256 value) internal pure returns (string memory) {
                      if (value == 0) {
                          return "0x00";
                      }
                      uint256 temp = value;
                      uint256 length = 0;
                      while (temp != 0) {
                          length++;
                          temp >>= 8;
                      }
                      return toHexString(value, length);
                  }
                  /**
                   * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
                   */
                  function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
                      bytes memory buffer = new bytes(2 * length + 2);
                      buffer[0] = "0";
                      buffer[1] = "x";
                      for (uint256 i = 2 * length + 1; i > 1; --i) {
                          buffer[i] = _HEX_SYMBOLS[value & 0xf];
                          value >>= 4;
                      }
                      require(value == 0, "Strings: hex length insufficient");
                      return string(buffer);
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
              pragma solidity ^0.8.0;
              import "./IERC165.sol";
              /**
               * @dev Implementation of the {IERC165} interface.
               *
               * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
               * for the additional interface id that will be supported. For example:
               *
               * ```solidity
               * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
               *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
               * }
               * ```
               *
               * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
               */
              abstract contract ERC165 is IERC165 {
                  /**
                   * @dev See {IERC165-supportsInterface}.
                   */
                  function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
                      return interfaceId == type(IERC165).interfaceId;
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
              pragma solidity ^0.8.0;
              /**
               * @dev Interface of the ERC165 standard, as defined in the
               * https://eips.ethereum.org/EIPS/eip-165[EIP].
               *
               * Implementers can declare support of contract interfaces, which can then be
               * queried by others ({ERC165Checker}).
               *
               * For an implementation, see {ERC165}.
               */
              interface IERC165 {
                  /**
                   * @dev Returns true if this contract implements the interface defined by
                   * `interfaceId`. See the corresponding
                   * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
                   * to learn more about how these ids are created.
                   *
                   * This function call must use less than 30 000 gas.
                   */
                  function supportsInterface(bytes4 interfaceId) external view returns (bool);
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)
              pragma solidity ^0.8.0;
              /**
               * @dev Interface of the ERC20 standard as defined in the EIP.
               */
              interface IERC20 {
                  /**
                   * @dev Emitted when `value` tokens are moved from one account (`from`) to
                   * another (`to`).
                   *
                   * Note that `value` may be zero.
                   */
                  event Transfer(address indexed from, address indexed to, uint256 value);
                  /**
                   * @dev Emitted when the allowance of a `spender` for an `owner` is set by
                   * a call to {approve}. `value` is the new allowance.
                   */
                  event Approval(address indexed owner, address indexed spender, uint256 value);
                  /**
                   * @dev Returns the amount of tokens in existence.
                   */
                  function totalSupply() external view returns (uint256);
                  /**
                   * @dev Returns the amount of tokens owned by `account`.
                   */
                  function balanceOf(address account) external view returns (uint256);
                  /**
                   * @dev Moves `amount` tokens from the caller's account to `to`.
                   *
                   * Returns a boolean value indicating whether the operation succeeded.
                   *
                   * Emits a {Transfer} event.
                   */
                  function transfer(address to, uint256 amount) external returns (bool);
                  /**
                   * @dev Returns the remaining number of tokens that `spender` will be
                   * allowed to spend on behalf of `owner` through {transferFrom}. This is
                   * zero by default.
                   *
                   * This value changes when {approve} or {transferFrom} are called.
                   */
                  function allowance(address owner, address spender) external view returns (uint256);
                  /**
                   * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
                   *
                   * Returns a boolean value indicating whether the operation succeeded.
                   *
                   * IMPORTANT: Beware that changing an allowance with this method brings the risk
                   * that someone may use both the old and the new allowance by unfortunate
                   * transaction ordering. One possible solution to mitigate this race
                   * condition is to first reduce the spender's allowance to 0 and set the
                   * desired value afterwards:
                   * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
                   *
                   * Emits an {Approval} event.
                   */
                  function approve(address spender, uint256 amount) external returns (bool);
                  /**
                   * @dev Moves `amount` tokens from `from` to `to` using the
                   * allowance mechanism. `amount` is then deducted from the caller's
                   * allowance.
                   *
                   * Returns a boolean value indicating whether the operation succeeded.
                   *
                   * Emits a {Transfer} event.
                   */
                  function transferFrom(
                      address from,
                      address to,
                      uint256 amount
                  ) external returns (bool);
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)
              pragma solidity ^0.8.1;
              /**
               * @dev Collection of functions related to the address type
               */
              library AddressUpgradeable {
                  /**
                   * @dev Returns true if `account` is a contract.
                   *
                   * [IMPORTANT]
                   * ====
                   * It is unsafe to assume that an address for which this function returns
                   * false is an externally-owned account (EOA) and not a contract.
                   *
                   * Among others, `isContract` will return false for the following
                   * types of addresses:
                   *
                   *  - an externally-owned account
                   *  - a contract in construction
                   *  - an address where a contract will be created
                   *  - an address where a contract lived, but was destroyed
                   * ====
                   *
                   * [IMPORTANT]
                   * ====
                   * You shouldn't rely on `isContract` to protect against flash loan attacks!
                   *
                   * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
                   * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
                   * constructor.
                   * ====
                   */
                  function isContract(address account) internal view returns (bool) {
                      // This method relies on extcodesize/address.code.length, which returns 0
                      // for contracts in construction, since the code is only stored at the end
                      // of the constructor execution.
                      return account.code.length > 0;
                  }
                  /**
                   * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
                   * `recipient`, forwarding all available gas and reverting on errors.
                   *
                   * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
                   * of certain opcodes, possibly making contracts go over the 2300 gas limit
                   * imposed by `transfer`, making them unable to receive funds via
                   * `transfer`. {sendValue} removes this limitation.
                   *
                   * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
                   *
                   * IMPORTANT: because control is transferred to `recipient`, care must be
                   * taken to not create reentrancy vulnerabilities. Consider using
                   * {ReentrancyGuard} or the
                   * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
                   */
                  function sendValue(address payable recipient, uint256 amount) internal {
                      require(address(this).balance >= amount, "Address: insufficient balance");
                      (bool success, ) = recipient.call{value: amount}("");
                      require(success, "Address: unable to send value, recipient may have reverted");
                  }
                  /**
                   * @dev Performs a Solidity function call using a low level `call`. A
                   * plain `call` is an unsafe replacement for a function call: use this
                   * function instead.
                   *
                   * If `target` reverts with a revert reason, it is bubbled up by this
                   * function (like regular Solidity function calls).
                   *
                   * Returns the raw returned data. To convert to the expected return value,
                   * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
                   *
                   * Requirements:
                   *
                   * - `target` must be a contract.
                   * - calling `target` with `data` must not revert.
                   *
                   * _Available since v3.1._
                   */
                  function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                      return functionCall(target, data, "Address: low-level call failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
                   * `errorMessage` as a fallback revert reason when `target` reverts.
                   *
                   * _Available since v3.1._
                   */
                  function functionCall(
                      address target,
                      bytes memory data,
                      string memory errorMessage
                  ) internal returns (bytes memory) {
                      return functionCallWithValue(target, data, 0, errorMessage);
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                   * but also transferring `value` wei to `target`.
                   *
                   * Requirements:
                   *
                   * - the calling contract must have an ETH balance of at least `value`.
                   * - the called Solidity function must be `payable`.
                   *
                   * _Available since v3.1._
                   */
                  function functionCallWithValue(
                      address target,
                      bytes memory data,
                      uint256 value
                  ) internal returns (bytes memory) {
                      return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
                   * with `errorMessage` as a fallback revert reason when `target` reverts.
                   *
                   * _Available since v3.1._
                   */
                  function functionCallWithValue(
                      address target,
                      bytes memory data,
                      uint256 value,
                      string memory errorMessage
                  ) internal returns (bytes memory) {
                      require(address(this).balance >= value, "Address: insufficient balance for call");
                      require(isContract(target), "Address: call to non-contract");
                      (bool success, bytes memory returndata) = target.call{value: value}(data);
                      return verifyCallResult(success, returndata, errorMessage);
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                   * but performing a static call.
                   *
                   * _Available since v3.3._
                   */
                  function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                      return functionStaticCall(target, data, "Address: low-level static call failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                   * but performing a static call.
                   *
                   * _Available since v3.3._
                   */
                  function functionStaticCall(
                      address target,
                      bytes memory data,
                      string memory errorMessage
                  ) internal view returns (bytes memory) {
                      require(isContract(target), "Address: static call to non-contract");
                      (bool success, bytes memory returndata) = target.staticcall(data);
                      return verifyCallResult(success, returndata, errorMessage);
                  }
                  /**
                   * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
                   * revert reason using the provided one.
                   *
                   * _Available since v4.3._
                   */
                  function verifyCallResult(
                      bool success,
                      bytes memory returndata,
                      string memory errorMessage
                  ) internal pure returns (bytes memory) {
                      if (success) {
                          return returndata;
                      } else {
                          // Look for revert reason and bubble it up if present
                          if (returndata.length > 0) {
                              // The easiest way to bubble the revert reason is using memory via assembly
                              assembly {
                                  let returndata_size := mload(returndata)
                                  revert(add(32, returndata), returndata_size)
                              }
                          } else {
                              revert(errorMessage);
                          }
                      }
                  }
              }
              

              File 6 of 7: QuadraticFundingVotingStrategyImplementation
              // SPDX-License-Identifier: AGPL-3.0-only
              pragma solidity 0.8.17;
              import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
              import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
              import "@openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol";
              import "@openzeppelin/contracts-upgradeable/token/ERC20/utils/SafeERC20Upgradeable.sol";
              import "../IVotingStrategy.sol";
              /**
               * Allows voters to cast multiple weighted votes to grants with one transaction
               * This is inspired from BulkCheckout documented over at:
               * https://github.com/gitcoinco/BulkTransactions/blob/master/contracts/BulkCheckout.sol
               *
               * Emits event upon every transfer.
               */
              contract QuadraticFundingVotingStrategyImplementation is IVotingStrategy, ReentrancyGuard, Initializable {
                using SafeERC20Upgradeable for IERC20Upgradeable;
                // --- Event ---
                /// @notice Emitted when a new vote is sent
                event Voted(
                  address  token,                   // voting token
                  uint256 amount,                   // voting amount
                  address indexed voter,            // voter address
                  address indexed grantAddress,     // grant address
                  address indexed roundAddress      // round address
                );
                // --- Core methods ---
                function initialize() external initializer {
                  // empty initializer
                }
                /**
                 * @notice Invoked by RoundImplementation which allows
                 * a voted to cast weighted votes to multiple grants during a round
                 *
                 * @dev
                 * - more voters -> higher the gas
                 * - this would be triggered when a voter casts their vote via grant explorer
                 * - can be invoked by the round
                 * - supports ERC20 and Native token transfer
                 *
                 * @param encodedVotes encoded list of votes
                 * @param voterAddress voter address
                 */
                function vote(bytes[] calldata encodedVotes, address voterAddress) external override payable nonReentrant isRoundContract {
                  /// @dev iterate over multiple donations and transfer funds
                  for (uint256 i = 0; i < encodedVotes.length; i++) {
                    (address _token, uint256 _amount, address _grantAddress) = abi.decode(encodedVotes[i], (address, uint256, address));
                    if (_token == address(0)) {
                      /// @dev native token transfer to grant address
                      // slither-disable-next-line reentrancy-events
                      AddressUpgradeable.sendValue(payable(_grantAddress), _amount);
                    } else {
                      /// @dev erc20 transfer to grant address
                      // slither-disable-next-line arbitrary-send-erc20,reentrancy-events,
                      SafeERC20Upgradeable.safeTransferFrom(
                        IERC20Upgradeable(_token),
                        voterAddress,
                        _grantAddress,
                        _amount
                      );
                    }
                    /// @dev emit event for transfer
                    emit Voted(
                      _token,
                      _amount,
                      voterAddress,
                      _grantAddress,
                      msg.sender
                    );
                  }
                }
              }// SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts (last updated v4.6.0) (proxy/utils/Initializable.sol)
              pragma solidity ^0.8.2;
              import "../../utils/AddressUpgradeable.sol";
              /**
               * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
               * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an
               * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
               * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
               *
               * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be
               * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in
               * case an upgrade adds a module that needs to be initialized.
               *
               * For example:
               *
               * [.hljs-theme-light.nopadding]
               * ```
               * contract MyToken is ERC20Upgradeable {
               *     function initialize() initializer public {
               *         __ERC20_init("MyToken", "MTK");
               *     }
               * }
               * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {
               *     function initializeV2() reinitializer(2) public {
               *         __ERC20Permit_init("MyToken");
               *     }
               * }
               * ```
               *
               * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
               * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
               *
               * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
               * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
               *
               * [CAUTION]
               * ====
               * Avoid leaving a contract uninitialized.
               *
               * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
               * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke
               * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:
               *
               * [.hljs-theme-light.nopadding]
               * ```
               * /// @custom:oz-upgrades-unsafe-allow constructor
               * constructor() {
               *     _disableInitializers();
               * }
               * ```
               * ====
               */
              abstract contract Initializable {
                  /**
                   * @dev Indicates that the contract has been initialized.
                   * @custom:oz-retyped-from bool
                   */
                  uint8 private _initialized;
                  /**
                   * @dev Indicates that the contract is in the process of being initialized.
                   */
                  bool private _initializing;
                  /**
                   * @dev Triggered when the contract has been initialized or reinitialized.
                   */
                  event Initialized(uint8 version);
                  /**
                   * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
                   * `onlyInitializing` functions can be used to initialize parent contracts. Equivalent to `reinitializer(1)`.
                   */
                  modifier initializer() {
                      bool isTopLevelCall = _setInitializedVersion(1);
                      if (isTopLevelCall) {
                          _initializing = true;
                      }
                      _;
                      if (isTopLevelCall) {
                          _initializing = false;
                          emit Initialized(1);
                      }
                  }
                  /**
                   * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
                   * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
                   * used to initialize parent contracts.
                   *
                   * `initializer` is equivalent to `reinitializer(1)`, so a reinitializer may be used after the original
                   * initialization step. This is essential to configure modules that are added through upgrades and that require
                   * initialization.
                   *
                   * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
                   * a contract, executing them in the right order is up to the developer or operator.
                   */
                  modifier reinitializer(uint8 version) {
                      bool isTopLevelCall = _setInitializedVersion(version);
                      if (isTopLevelCall) {
                          _initializing = true;
                      }
                      _;
                      if (isTopLevelCall) {
                          _initializing = false;
                          emit Initialized(version);
                      }
                  }
                  /**
                   * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
                   * {initializer} and {reinitializer} modifiers, directly or indirectly.
                   */
                  modifier onlyInitializing() {
                      require(_initializing, "Initializable: contract is not initializing");
                      _;
                  }
                  /**
                   * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.
                   * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized
                   * to any version. It is recommended to use this to lock implementation contracts that are designed to be called
                   * through proxies.
                   */
                  function _disableInitializers() internal virtual {
                      _setInitializedVersion(type(uint8).max);
                  }
                  function _setInitializedVersion(uint8 version) private returns (bool) {
                      // If the contract is initializing we ignore whether _initialized is set in order to support multiple
                      // inheritance patterns, but we only do this in the context of a constructor, and for the lowest level
                      // of initializers, because in other contexts the contract may have been reentered.
                      if (_initializing) {
                          require(
                              version == 1 && !AddressUpgradeable.isContract(address(this)),
                              "Initializable: contract is already initialized"
                          );
                          return false;
                      } else {
                          require(_initialized < version, "Initializable: contract is already initialized");
                          _initialized = version;
                          return true;
                      }
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)
              pragma solidity ^0.8.0;
              /**
               * @dev Contract module that helps prevent reentrant calls to a function.
               *
               * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
               * available, which can be applied to functions to make sure there are no nested
               * (reentrant) calls to them.
               *
               * Note that because there is a single `nonReentrant` guard, functions marked as
               * `nonReentrant` may not call one another. This can be worked around by making
               * those functions `private`, and then adding `external` `nonReentrant` entry
               * points to them.
               *
               * TIP: If you would like to learn more about reentrancy and alternative ways
               * to protect against it, check out our blog post
               * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
               */
              abstract contract ReentrancyGuard {
                  // Booleans are more expensive than uint256 or any type that takes up a full
                  // word because each write operation emits an extra SLOAD to first read the
                  // slot's contents, replace the bits taken up by the boolean, and then write
                  // back. This is the compiler's defense against contract upgrades and
                  // pointer aliasing, and it cannot be disabled.
                  // The values being non-zero value makes deployment a bit more expensive,
                  // but in exchange the refund on every call to nonReentrant will be lower in
                  // amount. Since refunds are capped to a percentage of the total
                  // transaction's gas, it is best to keep them low in cases like this one, to
                  // increase the likelihood of the full refund coming into effect.
                  uint256 private constant _NOT_ENTERED = 1;
                  uint256 private constant _ENTERED = 2;
                  uint256 private _status;
                  constructor() {
                      _status = _NOT_ENTERED;
                  }
                  /**
                   * @dev Prevents a contract from calling itself, directly or indirectly.
                   * Calling a `nonReentrant` function from another `nonReentrant`
                   * function is not supported. It is possible to prevent this from happening
                   * by making the `nonReentrant` function external, and making it call a
                   * `private` function that does the actual work.
                   */
                  modifier nonReentrant() {
                      // On the first call to nonReentrant, _notEntered will be true
                      require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
                      // Any calls to nonReentrant after this point will fail
                      _status = _ENTERED;
                      _;
                      // By storing the original value once again, a refund is triggered (see
                      // https://eips.ethereum.org/EIPS/eip-2200)
                      _status = _NOT_ENTERED;
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)
              pragma solidity ^0.8.1;
              /**
               * @dev Collection of functions related to the address type
               */
              library AddressUpgradeable {
                  /**
                   * @dev Returns true if `account` is a contract.
                   *
                   * [IMPORTANT]
                   * ====
                   * It is unsafe to assume that an address for which this function returns
                   * false is an externally-owned account (EOA) and not a contract.
                   *
                   * Among others, `isContract` will return false for the following
                   * types of addresses:
                   *
                   *  - an externally-owned account
                   *  - a contract in construction
                   *  - an address where a contract will be created
                   *  - an address where a contract lived, but was destroyed
                   * ====
                   *
                   * [IMPORTANT]
                   * ====
                   * You shouldn't rely on `isContract` to protect against flash loan attacks!
                   *
                   * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
                   * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
                   * constructor.
                   * ====
                   */
                  function isContract(address account) internal view returns (bool) {
                      // This method relies on extcodesize/address.code.length, which returns 0
                      // for contracts in construction, since the code is only stored at the end
                      // of the constructor execution.
                      return account.code.length > 0;
                  }
                  /**
                   * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
                   * `recipient`, forwarding all available gas and reverting on errors.
                   *
                   * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
                   * of certain opcodes, possibly making contracts go over the 2300 gas limit
                   * imposed by `transfer`, making them unable to receive funds via
                   * `transfer`. {sendValue} removes this limitation.
                   *
                   * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
                   *
                   * IMPORTANT: because control is transferred to `recipient`, care must be
                   * taken to not create reentrancy vulnerabilities. Consider using
                   * {ReentrancyGuard} or the
                   * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
                   */
                  function sendValue(address payable recipient, uint256 amount) internal {
                      require(address(this).balance >= amount, "Address: insufficient balance");
                      (bool success, ) = recipient.call{value: amount}("");
                      require(success, "Address: unable to send value, recipient may have reverted");
                  }
                  /**
                   * @dev Performs a Solidity function call using a low level `call`. A
                   * plain `call` is an unsafe replacement for a function call: use this
                   * function instead.
                   *
                   * If `target` reverts with a revert reason, it is bubbled up by this
                   * function (like regular Solidity function calls).
                   *
                   * Returns the raw returned data. To convert to the expected return value,
                   * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
                   *
                   * Requirements:
                   *
                   * - `target` must be a contract.
                   * - calling `target` with `data` must not revert.
                   *
                   * _Available since v3.1._
                   */
                  function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                      return functionCall(target, data, "Address: low-level call failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
                   * `errorMessage` as a fallback revert reason when `target` reverts.
                   *
                   * _Available since v3.1._
                   */
                  function functionCall(
                      address target,
                      bytes memory data,
                      string memory errorMessage
                  ) internal returns (bytes memory) {
                      return functionCallWithValue(target, data, 0, errorMessage);
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                   * but also transferring `value` wei to `target`.
                   *
                   * Requirements:
                   *
                   * - the calling contract must have an ETH balance of at least `value`.
                   * - the called Solidity function must be `payable`.
                   *
                   * _Available since v3.1._
                   */
                  function functionCallWithValue(
                      address target,
                      bytes memory data,
                      uint256 value
                  ) internal returns (bytes memory) {
                      return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
                   * with `errorMessage` as a fallback revert reason when `target` reverts.
                   *
                   * _Available since v3.1._
                   */
                  function functionCallWithValue(
                      address target,
                      bytes memory data,
                      uint256 value,
                      string memory errorMessage
                  ) internal returns (bytes memory) {
                      require(address(this).balance >= value, "Address: insufficient balance for call");
                      require(isContract(target), "Address: call to non-contract");
                      (bool success, bytes memory returndata) = target.call{value: value}(data);
                      return verifyCallResult(success, returndata, errorMessage);
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                   * but performing a static call.
                   *
                   * _Available since v3.3._
                   */
                  function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                      return functionStaticCall(target, data, "Address: low-level static call failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                   * but performing a static call.
                   *
                   * _Available since v3.3._
                   */
                  function functionStaticCall(
                      address target,
                      bytes memory data,
                      string memory errorMessage
                  ) internal view returns (bytes memory) {
                      require(isContract(target), "Address: static call to non-contract");
                      (bool success, bytes memory returndata) = target.staticcall(data);
                      return verifyCallResult(success, returndata, errorMessage);
                  }
                  /**
                   * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
                   * revert reason using the provided one.
                   *
                   * _Available since v4.3._
                   */
                  function verifyCallResult(
                      bool success,
                      bytes memory returndata,
                      string memory errorMessage
                  ) internal pure returns (bytes memory) {
                      if (success) {
                          return returndata;
                      } else {
                          // Look for revert reason and bubble it up if present
                          if (returndata.length > 0) {
                              // The easiest way to bubble the revert reason is using memory via assembly
                              assembly {
                                  let returndata_size := mload(returndata)
                                  revert(add(32, returndata), returndata_size)
                              }
                          } else {
                              revert(errorMessage);
                          }
                      }
                  }
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)
              pragma solidity ^0.8.0;
              import "../IERC20Upgradeable.sol";
              import "../../../utils/AddressUpgradeable.sol";
              /**
               * @title SafeERC20
               * @dev Wrappers around ERC20 operations that throw on failure (when the token
               * contract returns false). Tokens that return no value (and instead revert or
               * throw on failure) are also supported, non-reverting calls are assumed to be
               * successful.
               * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
               * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
               */
              library SafeERC20Upgradeable {
                  using AddressUpgradeable for address;
                  function safeTransfer(
                      IERC20Upgradeable token,
                      address to,
                      uint256 value
                  ) internal {
                      _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
                  }
                  function safeTransferFrom(
                      IERC20Upgradeable token,
                      address from,
                      address to,
                      uint256 value
                  ) internal {
                      _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
                  }
                  /**
                   * @dev Deprecated. This function has issues similar to the ones found in
                   * {IERC20-approve}, and its usage is discouraged.
                   *
                   * Whenever possible, use {safeIncreaseAllowance} and
                   * {safeDecreaseAllowance} instead.
                   */
                  function safeApprove(
                      IERC20Upgradeable token,
                      address spender,
                      uint256 value
                  ) internal {
                      // safeApprove should only be called when setting an initial allowance,
                      // or when resetting it to zero. To increase and decrease it, use
                      // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
                      require(
                          (value == 0) || (token.allowance(address(this), spender) == 0),
                          "SafeERC20: approve from non-zero to non-zero allowance"
                      );
                      _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
                  }
                  function safeIncreaseAllowance(
                      IERC20Upgradeable token,
                      address spender,
                      uint256 value
                  ) internal {
                      uint256 newAllowance = token.allowance(address(this), spender) + value;
                      _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
                  }
                  function safeDecreaseAllowance(
                      IERC20Upgradeable token,
                      address spender,
                      uint256 value
                  ) internal {
                      unchecked {
                          uint256 oldAllowance = token.allowance(address(this), spender);
                          require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
                          uint256 newAllowance = oldAllowance - value;
                          _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
                      }
                  }
                  /**
                   * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
                   * on the return value: the return value is optional (but if data is returned, it must not be false).
                   * @param token The token targeted by the call.
                   * @param data The call data (encoded using abi.encode or one of its variants).
                   */
                  function _callOptionalReturn(IERC20Upgradeable token, bytes memory data) private {
                      // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
                      // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
                      // the target address contains contract code and also asserts for success in the low-level call.
                      bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
                      if (returndata.length > 0) {
                          // Return data is optional
                          require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
                      }
                  }
              }
              // SPDX-License-Identifier: AGPL-3.0-only
              pragma solidity 0.8.17;
              /**
               * @notice Defines the abstract contract for voting algorithms on grants
               * within a round. Any new voting algorithm would be expected to
               * extend this abstract contract.
               * Every IVotingStrategy contract would be unique to RoundImplementation
               * and would be deployed before creating a round
               */
              abstract contract IVotingStrategy {
                 // --- Data ---
                /// @notice Round address
                address public roundAddress;
                // --- Modifier ---
                /// @notice modifier to check if sender is round contract.
                modifier isRoundContract() {
                  require(roundAddress != address(0), "error: voting contract not linked to a round");
                  require(msg.sender == roundAddress, "error: can be invoked only by round contract");
                  _;
                }
                // --- Core methods ---
                /**
                 * @notice Invoked by RoundImplementation on creation to
                 * set the round for which the voting contracts is to be used
                 *
                 */
                function init() external {
                  require(roundAddress == address(0), "init: roundAddress already set");
                  roundAddress = msg.sender;
                }
                /**
                 * @notice Invoked by RoundImplementation to allow voter to case
                 * vote for grants during a round.
                 *
                 * @dev
                 * - allows contributor to do cast multiple votes which could be weighted.
                 * - should be invoked by RoundImplementation contract
                 * - ideally IVotingStrategy implementation should emit events after a vote is cast
                 * - this would be triggered when a voter casts their vote via grant explorer
                 *
                 * @param _encodedVotes encoded votes
                 * @param _voterAddress voter address
                 */
                function vote(bytes[] calldata _encodedVotes, address _voterAddress) external virtual payable;
              }
              // SPDX-License-Identifier: MIT
              // OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)
              pragma solidity ^0.8.0;
              /**
               * @dev Interface of the ERC20 standard as defined in the EIP.
               */
              interface IERC20Upgradeable {
                  /**
                   * @dev Emitted when `value` tokens are moved from one account (`from`) to
                   * another (`to`).
                   *
                   * Note that `value` may be zero.
                   */
                  event Transfer(address indexed from, address indexed to, uint256 value);
                  /**
                   * @dev Emitted when the allowance of a `spender` for an `owner` is set by
                   * a call to {approve}. `value` is the new allowance.
                   */
                  event Approval(address indexed owner, address indexed spender, uint256 value);
                  /**
                   * @dev Returns the amount of tokens in existence.
                   */
                  function totalSupply() external view returns (uint256);
                  /**
                   * @dev Returns the amount of tokens owned by `account`.
                   */
                  function balanceOf(address account) external view returns (uint256);
                  /**
                   * @dev Moves `amount` tokens from the caller's account to `to`.
                   *
                   * Returns a boolean value indicating whether the operation succeeded.
                   *
                   * Emits a {Transfer} event.
                   */
                  function transfer(address to, uint256 amount) external returns (bool);
                  /**
                   * @dev Returns the remaining number of tokens that `spender` will be
                   * allowed to spend on behalf of `owner` through {transferFrom}. This is
                   * zero by default.
                   *
                   * This value changes when {approve} or {transferFrom} are called.
                   */
                  function allowance(address owner, address spender) external view returns (uint256);
                  /**
                   * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
                   *
                   * Returns a boolean value indicating whether the operation succeeded.
                   *
                   * IMPORTANT: Beware that changing an allowance with this method brings the risk
                   * that someone may use both the old and the new allowance by unfortunate
                   * transaction ordering. One possible solution to mitigate this race
                   * condition is to first reduce the spender's allowance to 0 and set the
                   * desired value afterwards:
                   * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
                   *
                   * Emits an {Approval} event.
                   */
                  function approve(address spender, uint256 amount) external returns (bool);
                  /**
                   * @dev Moves `amount` tokens from `from` to `to` using the
                   * allowance mechanism. `amount` is then deducted from the caller's
                   * allowance.
                   *
                   * Returns a boolean value indicating whether the operation succeeded.
                   *
                   * Emits a {Transfer} event.
                   */
                  function transferFrom(
                      address from,
                      address to,
                      uint256 amount
                  ) external returns (bool);
              }
              

              File 7 of 7: GnosisSafe
              // SPDX-License-Identifier: LGPL-3.0-only
              pragma solidity >=0.7.0 <0.9.0;
              import "./base/ModuleManager.sol";
              import "./base/OwnerManager.sol";
              import "./base/FallbackManager.sol";
              import "./base/GuardManager.sol";
              import "./common/EtherPaymentFallback.sol";
              import "./common/Singleton.sol";
              import "./common/SignatureDecoder.sol";
              import "./common/SecuredTokenTransfer.sol";
              import "./common/StorageAccessible.sol";
              import "./interfaces/ISignatureValidator.sol";
              import "./external/GnosisSafeMath.sol";
              /// @title Gnosis Safe - A multisignature wallet with support for confirmations using signed messages based on ERC191.
              /// @author Stefan George - <stefan@gnosis.io>
              /// @author Richard Meissner - <richard@gnosis.io>
              contract GnosisSafe is
                  EtherPaymentFallback,
                  Singleton,
                  ModuleManager,
                  OwnerManager,
                  SignatureDecoder,
                  SecuredTokenTransfer,
                  ISignatureValidatorConstants,
                  FallbackManager,
                  StorageAccessible,
                  GuardManager
              {
                  using GnosisSafeMath for uint256;
                  string public constant VERSION = "1.3.0";
                  // keccak256(
                  //     "EIP712Domain(uint256 chainId,address verifyingContract)"
                  // );
                  bytes32 private constant DOMAIN_SEPARATOR_TYPEHASH = 0x47e79534a245952e8b16893a336b85a3d9ea9fa8c573f3d803afb92a79469218;
                  // keccak256(
                  //     "SafeTx(address to,uint256 value,bytes data,uint8 operation,uint256 safeTxGas,uint256 baseGas,uint256 gasPrice,address gasToken,address refundReceiver,uint256 nonce)"
                  // );
                  bytes32 private constant SAFE_TX_TYPEHASH = 0xbb8310d486368db6bd6f849402fdd73ad53d316b5a4b2644ad6efe0f941286d8;
                  event SafeSetup(address indexed initiator, address[] owners, uint256 threshold, address initializer, address fallbackHandler);
                  event ApproveHash(bytes32 indexed approvedHash, address indexed owner);
                  event SignMsg(bytes32 indexed msgHash);
                  event ExecutionFailure(bytes32 txHash, uint256 payment);
                  event ExecutionSuccess(bytes32 txHash, uint256 payment);
                  uint256 public nonce;
                  bytes32 private _deprecatedDomainSeparator;
                  // Mapping to keep track of all message hashes that have been approve by ALL REQUIRED owners
                  mapping(bytes32 => uint256) public signedMessages;
                  // Mapping to keep track of all hashes (message or transaction) that have been approve by ANY owners
                  mapping(address => mapping(bytes32 => uint256)) public approvedHashes;
                  // This constructor ensures that this contract can only be used as a master copy for Proxy contracts
                  constructor() {
                      // By setting the threshold it is not possible to call setup anymore,
                      // so we create a Safe with 0 owners and threshold 1.
                      // This is an unusable Safe, perfect for the singleton
                      threshold = 1;
                  }
                  /// @dev Setup function sets initial storage of contract.
                  /// @param _owners List of Safe owners.
                  /// @param _threshold Number of required confirmations for a Safe transaction.
                  /// @param to Contract address for optional delegate call.
                  /// @param data Data payload for optional delegate call.
                  /// @param fallbackHandler Handler for fallback calls to this contract
                  /// @param paymentToken Token that should be used for the payment (0 is ETH)
                  /// @param payment Value that should be paid
                  /// @param paymentReceiver Adddress that should receive the payment (or 0 if tx.origin)
                  function setup(
                      address[] calldata _owners,
                      uint256 _threshold,
                      address to,
                      bytes calldata data,
                      address fallbackHandler,
                      address paymentToken,
                      uint256 payment,
                      address payable paymentReceiver
                  ) external {
                      // setupOwners checks if the Threshold is already set, therefore preventing that this method is called twice
                      setupOwners(_owners, _threshold);
                      if (fallbackHandler != address(0)) internalSetFallbackHandler(fallbackHandler);
                      // As setupOwners can only be called if the contract has not been initialized we don't need a check for setupModules
                      setupModules(to, data);
                      if (payment > 0) {
                          // To avoid running into issues with EIP-170 we reuse the handlePayment function (to avoid adjusting code of that has been verified we do not adjust the method itself)
                          // baseGas = 0, gasPrice = 1 and gas = payment => amount = (payment + 0) * 1 = payment
                          handlePayment(payment, 0, 1, paymentToken, paymentReceiver);
                      }
                      emit SafeSetup(msg.sender, _owners, _threshold, to, fallbackHandler);
                  }
                  /// @dev Allows to execute a Safe transaction confirmed by required number of owners and then pays the account that submitted the transaction.
                  ///      Note: The fees are always transferred, even if the user transaction fails.
                  /// @param to Destination address of Safe transaction.
                  /// @param value Ether value of Safe transaction.
                  /// @param data Data payload of Safe transaction.
                  /// @param operation Operation type of Safe transaction.
                  /// @param safeTxGas Gas that should be used for the Safe transaction.
                  /// @param baseGas Gas costs that are independent of the transaction execution(e.g. base transaction fee, signature check, payment of the refund)
                  /// @param gasPrice Gas price that should be used for the payment calculation.
                  /// @param gasToken Token address (or 0 if ETH) that is used for the payment.
                  /// @param refundReceiver Address of receiver of gas payment (or 0 if tx.origin).
                  /// @param signatures Packed signature data ({bytes32 r}{bytes32 s}{uint8 v})
                  function execTransaction(
                      address to,
                      uint256 value,
                      bytes calldata data,
                      Enum.Operation operation,
                      uint256 safeTxGas,
                      uint256 baseGas,
                      uint256 gasPrice,
                      address gasToken,
                      address payable refundReceiver,
                      bytes memory signatures
                  ) public payable virtual returns (bool success) {
                      bytes32 txHash;
                      // Use scope here to limit variable lifetime and prevent `stack too deep` errors
                      {
                          bytes memory txHashData =
                              encodeTransactionData(
                                  // Transaction info
                                  to,
                                  value,
                                  data,
                                  operation,
                                  safeTxGas,
                                  // Payment info
                                  baseGas,
                                  gasPrice,
                                  gasToken,
                                  refundReceiver,
                                  // Signature info
                                  nonce
                              );
                          // Increase nonce and execute transaction.
                          nonce++;
                          txHash = keccak256(txHashData);
                          checkSignatures(txHash, txHashData, signatures);
                      }
                      address guard = getGuard();
                      {
                          if (guard != address(0)) {
                              Guard(guard).checkTransaction(
                                  // Transaction info
                                  to,
                                  value,
                                  data,
                                  operation,
                                  safeTxGas,
                                  // Payment info
                                  baseGas,
                                  gasPrice,
                                  gasToken,
                                  refundReceiver,
                                  // Signature info
                                  signatures,
                                  msg.sender
                              );
                          }
                      }
                      // We require some gas to emit the events (at least 2500) after the execution and some to perform code until the execution (500)
                      // We also include the 1/64 in the check that is not send along with a call to counteract potential shortings because of EIP-150
                      require(gasleft() >= ((safeTxGas * 64) / 63).max(safeTxGas + 2500) + 500, "GS010");
                      // Use scope here to limit variable lifetime and prevent `stack too deep` errors
                      {
                          uint256 gasUsed = gasleft();
                          // If the gasPrice is 0 we assume that nearly all available gas can be used (it is always more than safeTxGas)
                          // We only substract 2500 (compared to the 3000 before) to ensure that the amount passed is still higher than safeTxGas
                          success = execute(to, value, data, operation, gasPrice == 0 ? (gasleft() - 2500) : safeTxGas);
                          gasUsed = gasUsed.sub(gasleft());
                          // If no safeTxGas and no gasPrice was set (e.g. both are 0), then the internal tx is required to be successful
                          // This makes it possible to use `estimateGas` without issues, as it searches for the minimum gas where the tx doesn't revert
                          require(success || safeTxGas != 0 || gasPrice != 0, "GS013");
                          // We transfer the calculated tx costs to the tx.origin to avoid sending it to intermediate contracts that have made calls
                          uint256 payment = 0;
                          if (gasPrice > 0) {
                              payment = handlePayment(gasUsed, baseGas, gasPrice, gasToken, refundReceiver);
                          }
                          if (success) emit ExecutionSuccess(txHash, payment);
                          else emit ExecutionFailure(txHash, payment);
                      }
                      {
                          if (guard != address(0)) {
                              Guard(guard).checkAfterExecution(txHash, success);
                          }
                      }
                  }
                  function handlePayment(
                      uint256 gasUsed,
                      uint256 baseGas,
                      uint256 gasPrice,
                      address gasToken,
                      address payable refundReceiver
                  ) private returns (uint256 payment) {
                      // solhint-disable-next-line avoid-tx-origin
                      address payable receiver = refundReceiver == address(0) ? payable(tx.origin) : refundReceiver;
                      if (gasToken == address(0)) {
                          // For ETH we will only adjust the gas price to not be higher than the actual used gas price
                          payment = gasUsed.add(baseGas).mul(gasPrice < tx.gasprice ? gasPrice : tx.gasprice);
                          require(receiver.send(payment), "GS011");
                      } else {
                          payment = gasUsed.add(baseGas).mul(gasPrice);
                          require(transferToken(gasToken, receiver, payment), "GS012");
                      }
                  }
                  /**
                   * @dev Checks whether the signature provided is valid for the provided data, hash. Will revert otherwise.
                   * @param dataHash Hash of the data (could be either a message hash or transaction hash)
                   * @param data That should be signed (this is passed to an external validator contract)
                   * @param signatures Signature data that should be verified. Can be ECDSA signature, contract signature (EIP-1271) or approved hash.
                   */
                  function checkSignatures(
                      bytes32 dataHash,
                      bytes memory data,
                      bytes memory signatures
                  ) public view {
                      // Load threshold to avoid multiple storage loads
                      uint256 _threshold = threshold;
                      // Check that a threshold is set
                      require(_threshold > 0, "GS001");
                      checkNSignatures(dataHash, data, signatures, _threshold);
                  }
                  /**
                   * @dev Checks whether the signature provided is valid for the provided data, hash. Will revert otherwise.
                   * @param dataHash Hash of the data (could be either a message hash or transaction hash)
                   * @param data That should be signed (this is passed to an external validator contract)
                   * @param signatures Signature data that should be verified. Can be ECDSA signature, contract signature (EIP-1271) or approved hash.
                   * @param requiredSignatures Amount of required valid signatures.
                   */
                  function checkNSignatures(
                      bytes32 dataHash,
                      bytes memory data,
                      bytes memory signatures,
                      uint256 requiredSignatures
                  ) public view {
                      // Check that the provided signature data is not too short
                      require(signatures.length >= requiredSignatures.mul(65), "GS020");
                      // There cannot be an owner with address 0.
                      address lastOwner = address(0);
                      address currentOwner;
                      uint8 v;
                      bytes32 r;
                      bytes32 s;
                      uint256 i;
                      for (i = 0; i < requiredSignatures; i++) {
                          (v, r, s) = signatureSplit(signatures, i);
                          if (v == 0) {
                              // If v is 0 then it is a contract signature
                              // When handling contract signatures the address of the contract is encoded into r
                              currentOwner = address(uint160(uint256(r)));
                              // Check that signature data pointer (s) is not pointing inside the static part of the signatures bytes
                              // This check is not completely accurate, since it is possible that more signatures than the threshold are send.
                              // Here we only check that the pointer is not pointing inside the part that is being processed
                              require(uint256(s) >= requiredSignatures.mul(65), "GS021");
                              // Check that signature data pointer (s) is in bounds (points to the length of data -> 32 bytes)
                              require(uint256(s).add(32) <= signatures.length, "GS022");
                              // Check if the contract signature is in bounds: start of data is s + 32 and end is start + signature length
                              uint256 contractSignatureLen;
                              // solhint-disable-next-line no-inline-assembly
                              assembly {
                                  contractSignatureLen := mload(add(add(signatures, s), 0x20))
                              }
                              require(uint256(s).add(32).add(contractSignatureLen) <= signatures.length, "GS023");
                              // Check signature
                              bytes memory contractSignature;
                              // solhint-disable-next-line no-inline-assembly
                              assembly {
                                  // The signature data for contract signatures is appended to the concatenated signatures and the offset is stored in s
                                  contractSignature := add(add(signatures, s), 0x20)
                              }
                              require(ISignatureValidator(currentOwner).isValidSignature(data, contractSignature) == EIP1271_MAGIC_VALUE, "GS024");
                          } else if (v == 1) {
                              // If v is 1 then it is an approved hash
                              // When handling approved hashes the address of the approver is encoded into r
                              currentOwner = address(uint160(uint256(r)));
                              // Hashes are automatically approved by the sender of the message or when they have been pre-approved via a separate transaction
                              require(msg.sender == currentOwner || approvedHashes[currentOwner][dataHash] != 0, "GS025");
                          } else if (v > 30) {
                              // If v > 30 then default va (27,28) has been adjusted for eth_sign flow
                              // To support eth_sign and similar we adjust v and hash the messageHash with the Ethereum message prefix before applying ecrecover
                              currentOwner = ecrecover(keccak256(abi.encodePacked("\\x19Ethereum Signed Message:\
              32", dataHash)), v - 4, r, s);
                          } else {
                              // Default is the ecrecover flow with the provided data hash
                              // Use ecrecover with the messageHash for EOA signatures
                              currentOwner = ecrecover(dataHash, v, r, s);
                          }
                          require(currentOwner > lastOwner && owners[currentOwner] != address(0) && currentOwner != SENTINEL_OWNERS, "GS026");
                          lastOwner = currentOwner;
                      }
                  }
                  /// @dev Allows to estimate a Safe transaction.
                  ///      This method is only meant for estimation purpose, therefore the call will always revert and encode the result in the revert data.
                  ///      Since the `estimateGas` function includes refunds, call this method to get an estimated of the costs that are deducted from the safe with `execTransaction`
                  /// @param to Destination address of Safe transaction.
                  /// @param value Ether value of Safe transaction.
                  /// @param data Data payload of Safe transaction.
                  /// @param operation Operation type of Safe transaction.
                  /// @return Estimate without refunds and overhead fees (base transaction and payload data gas costs).
                  /// @notice Deprecated in favor of common/StorageAccessible.sol and will be removed in next version.
                  function requiredTxGas(
                      address to,
                      uint256 value,
                      bytes calldata data,
                      Enum.Operation operation
                  ) external returns (uint256) {
                      uint256 startGas = gasleft();
                      // We don't provide an error message here, as we use it to return the estimate
                      require(execute(to, value, data, operation, gasleft()));
                      uint256 requiredGas = startGas - gasleft();
                      // Convert response to string and return via error message
                      revert(string(abi.encodePacked(requiredGas)));
                  }
                  /**
                   * @dev Marks a hash as approved. This can be used to validate a hash that is used by a signature.
                   * @param hashToApprove The hash that should be marked as approved for signatures that are verified by this contract.
                   */
                  function approveHash(bytes32 hashToApprove) external {
                      require(owners[msg.sender] != address(0), "GS030");
                      approvedHashes[msg.sender][hashToApprove] = 1;
                      emit ApproveHash(hashToApprove, msg.sender);
                  }
                  /// @dev Returns the chain id used by this contract.
                  function getChainId() public view returns (uint256) {
                      uint256 id;
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          id := chainid()
                      }
                      return id;
                  }
                  function domainSeparator() public view returns (bytes32) {
                      return keccak256(abi.encode(DOMAIN_SEPARATOR_TYPEHASH, getChainId(), this));
                  }
                  /// @dev Returns the bytes that are hashed to be signed by owners.
                  /// @param to Destination address.
                  /// @param value Ether value.
                  /// @param data Data payload.
                  /// @param operation Operation type.
                  /// @param safeTxGas Gas that should be used for the safe transaction.
                  /// @param baseGas Gas costs for that are independent of the transaction execution(e.g. base transaction fee, signature check, payment of the refund)
                  /// @param gasPrice Maximum gas price that should be used for this transaction.
                  /// @param gasToken Token address (or 0 if ETH) that is used for the payment.
                  /// @param refundReceiver Address of receiver of gas payment (or 0 if tx.origin).
                  /// @param _nonce Transaction nonce.
                  /// @return Transaction hash bytes.
                  function encodeTransactionData(
                      address to,
                      uint256 value,
                      bytes calldata data,
                      Enum.Operation operation,
                      uint256 safeTxGas,
                      uint256 baseGas,
                      uint256 gasPrice,
                      address gasToken,
                      address refundReceiver,
                      uint256 _nonce
                  ) public view returns (bytes memory) {
                      bytes32 safeTxHash =
                          keccak256(
                              abi.encode(
                                  SAFE_TX_TYPEHASH,
                                  to,
                                  value,
                                  keccak256(data),
                                  operation,
                                  safeTxGas,
                                  baseGas,
                                  gasPrice,
                                  gasToken,
                                  refundReceiver,
                                  _nonce
                              )
                          );
                      return abi.encodePacked(bytes1(0x19), bytes1(0x01), domainSeparator(), safeTxHash);
                  }
                  /// @dev Returns hash to be signed by owners.
                  /// @param to Destination address.
                  /// @param value Ether value.
                  /// @param data Data payload.
                  /// @param operation Operation type.
                  /// @param safeTxGas Fas that should be used for the safe transaction.
                  /// @param baseGas Gas costs for data used to trigger the safe transaction.
                  /// @param gasPrice Maximum gas price that should be used for this transaction.
                  /// @param gasToken Token address (or 0 if ETH) that is used for the payment.
                  /// @param refundReceiver Address of receiver of gas payment (or 0 if tx.origin).
                  /// @param _nonce Transaction nonce.
                  /// @return Transaction hash.
                  function getTransactionHash(
                      address to,
                      uint256 value,
                      bytes calldata data,
                      Enum.Operation operation,
                      uint256 safeTxGas,
                      uint256 baseGas,
                      uint256 gasPrice,
                      address gasToken,
                      address refundReceiver,
                      uint256 _nonce
                  ) public view returns (bytes32) {
                      return keccak256(encodeTransactionData(to, value, data, operation, safeTxGas, baseGas, gasPrice, gasToken, refundReceiver, _nonce));
                  }
              }
              // SPDX-License-Identifier: LGPL-3.0-only
              pragma solidity >=0.7.0 <0.9.0;
              import "../common/Enum.sol";
              /// @title Executor - A contract that can execute transactions
              /// @author Richard Meissner - <richard@gnosis.pm>
              contract Executor {
                  function execute(
                      address to,
                      uint256 value,
                      bytes memory data,
                      Enum.Operation operation,
                      uint256 txGas
                  ) internal returns (bool success) {
                      if (operation == Enum.Operation.DelegateCall) {
                          // solhint-disable-next-line no-inline-assembly
                          assembly {
                              success := delegatecall(txGas, to, add(data, 0x20), mload(data), 0, 0)
                          }
                      } else {
                          // solhint-disable-next-line no-inline-assembly
                          assembly {
                              success := call(txGas, to, value, add(data, 0x20), mload(data), 0, 0)
                          }
                      }
                  }
              }
              // SPDX-License-Identifier: LGPL-3.0-only
              pragma solidity >=0.7.0 <0.9.0;
              import "../common/SelfAuthorized.sol";
              /// @title Fallback Manager - A contract that manages fallback calls made to this contract
              /// @author Richard Meissner - <richard@gnosis.pm>
              contract FallbackManager is SelfAuthorized {
                  event ChangedFallbackHandler(address handler);
                  // keccak256("fallback_manager.handler.address")
                  bytes32 internal constant FALLBACK_HANDLER_STORAGE_SLOT = 0x6c9a6c4a39284e37ed1cf53d337577d14212a4870fb976a4366c693b939918d5;
                  function internalSetFallbackHandler(address handler) internal {
                      bytes32 slot = FALLBACK_HANDLER_STORAGE_SLOT;
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          sstore(slot, handler)
                      }
                  }
                  /// @dev Allows to add a contract to handle fallback calls.
                  ///      Only fallback calls without value and with data will be forwarded.
                  ///      This can only be done via a Safe transaction.
                  /// @param handler contract to handle fallbacks calls.
                  function setFallbackHandler(address handler) public authorized {
                      internalSetFallbackHandler(handler);
                      emit ChangedFallbackHandler(handler);
                  }
                  // solhint-disable-next-line payable-fallback,no-complex-fallback
                  fallback() external {
                      bytes32 slot = FALLBACK_HANDLER_STORAGE_SLOT;
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          let handler := sload(slot)
                          if iszero(handler) {
                              return(0, 0)
                          }
                          calldatacopy(0, 0, calldatasize())
                          // The msg.sender address is shifted to the left by 12 bytes to remove the padding
                          // Then the address without padding is stored right after the calldata
                          mstore(calldatasize(), shl(96, caller()))
                          // Add 20 bytes for the address appended add the end
                          let success := call(gas(), handler, 0, 0, add(calldatasize(), 20), 0, 0)
                          returndatacopy(0, 0, returndatasize())
                          if iszero(success) {
                              revert(0, returndatasize())
                          }
                          return(0, returndatasize())
                      }
                  }
              }
              // SPDX-License-Identifier: LGPL-3.0-only
              pragma solidity >=0.7.0 <0.9.0;
              import "../common/Enum.sol";
              import "../common/SelfAuthorized.sol";
              interface Guard {
                  function checkTransaction(
                      address to,
                      uint256 value,
                      bytes memory data,
                      Enum.Operation operation,
                      uint256 safeTxGas,
                      uint256 baseGas,
                      uint256 gasPrice,
                      address gasToken,
                      address payable refundReceiver,
                      bytes memory signatures,
                      address msgSender
                  ) external;
                  function checkAfterExecution(bytes32 txHash, bool success) external;
              }
              /// @title Fallback Manager - A contract that manages fallback calls made to this contract
              /// @author Richard Meissner - <richard@gnosis.pm>
              contract GuardManager is SelfAuthorized {
                  event ChangedGuard(address guard);
                  // keccak256("guard_manager.guard.address")
                  bytes32 internal constant GUARD_STORAGE_SLOT = 0x4a204f620c8c5ccdca3fd54d003badd85ba500436a431f0cbda4f558c93c34c8;
                  /// @dev Set a guard that checks transactions before execution
                  /// @param guard The address of the guard to be used or the 0 address to disable the guard
                  function setGuard(address guard) external authorized {
                      bytes32 slot = GUARD_STORAGE_SLOT;
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          sstore(slot, guard)
                      }
                      emit ChangedGuard(guard);
                  }
                  function getGuard() internal view returns (address guard) {
                      bytes32 slot = GUARD_STORAGE_SLOT;
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          guard := sload(slot)
                      }
                  }
              }
              // SPDX-License-Identifier: LGPL-3.0-only
              pragma solidity >=0.7.0 <0.9.0;
              import "../common/Enum.sol";
              import "../common/SelfAuthorized.sol";
              import "./Executor.sol";
              /// @title Module Manager - A contract that manages modules that can execute transactions via this contract
              /// @author Stefan George - <stefan@gnosis.pm>
              /// @author Richard Meissner - <richard@gnosis.pm>
              contract ModuleManager is SelfAuthorized, Executor {
                  event EnabledModule(address module);
                  event DisabledModule(address module);
                  event ExecutionFromModuleSuccess(address indexed module);
                  event ExecutionFromModuleFailure(address indexed module);
                  address internal constant SENTINEL_MODULES = address(0x1);
                  mapping(address => address) internal modules;
                  function setupModules(address to, bytes memory data) internal {
                      require(modules[SENTINEL_MODULES] == address(0), "GS100");
                      modules[SENTINEL_MODULES] = SENTINEL_MODULES;
                      if (to != address(0))
                          // Setup has to complete successfully or transaction fails.
                          require(execute(to, 0, data, Enum.Operation.DelegateCall, gasleft()), "GS000");
                  }
                  /// @dev Allows to add a module to the whitelist.
                  ///      This can only be done via a Safe transaction.
                  /// @notice Enables the module `module` for the Safe.
                  /// @param module Module to be whitelisted.
                  function enableModule(address module) public authorized {
                      // Module address cannot be null or sentinel.
                      require(module != address(0) && module != SENTINEL_MODULES, "GS101");
                      // Module cannot be added twice.
                      require(modules[module] == address(0), "GS102");
                      modules[module] = modules[SENTINEL_MODULES];
                      modules[SENTINEL_MODULES] = module;
                      emit EnabledModule(module);
                  }
                  /// @dev Allows to remove a module from the whitelist.
                  ///      This can only be done via a Safe transaction.
                  /// @notice Disables the module `module` for the Safe.
                  /// @param prevModule Module that pointed to the module to be removed in the linked list
                  /// @param module Module to be removed.
                  function disableModule(address prevModule, address module) public authorized {
                      // Validate module address and check that it corresponds to module index.
                      require(module != address(0) && module != SENTINEL_MODULES, "GS101");
                      require(modules[prevModule] == module, "GS103");
                      modules[prevModule] = modules[module];
                      modules[module] = address(0);
                      emit DisabledModule(module);
                  }
                  /// @dev Allows a Module to execute a Safe transaction without any further confirmations.
                  /// @param to Destination address of module transaction.
                  /// @param value Ether value of module transaction.
                  /// @param data Data payload of module transaction.
                  /// @param operation Operation type of module transaction.
                  function execTransactionFromModule(
                      address to,
                      uint256 value,
                      bytes memory data,
                      Enum.Operation operation
                  ) public virtual returns (bool success) {
                      // Only whitelisted modules are allowed.
                      require(msg.sender != SENTINEL_MODULES && modules[msg.sender] != address(0), "GS104");
                      // Execute transaction without further confirmations.
                      success = execute(to, value, data, operation, gasleft());
                      if (success) emit ExecutionFromModuleSuccess(msg.sender);
                      else emit ExecutionFromModuleFailure(msg.sender);
                  }
                  /// @dev Allows a Module to execute a Safe transaction without any further confirmations and return data
                  /// @param to Destination address of module transaction.
                  /// @param value Ether value of module transaction.
                  /// @param data Data payload of module transaction.
                  /// @param operation Operation type of module transaction.
                  function execTransactionFromModuleReturnData(
                      address to,
                      uint256 value,
                      bytes memory data,
                      Enum.Operation operation
                  ) public returns (bool success, bytes memory returnData) {
                      success = execTransactionFromModule(to, value, data, operation);
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          // Load free memory location
                          let ptr := mload(0x40)
                          // We allocate memory for the return data by setting the free memory location to
                          // current free memory location + data size + 32 bytes for data size value
                          mstore(0x40, add(ptr, add(returndatasize(), 0x20)))
                          // Store the size
                          mstore(ptr, returndatasize())
                          // Store the data
                          returndatacopy(add(ptr, 0x20), 0, returndatasize())
                          // Point the return data to the correct memory location
                          returnData := ptr
                      }
                  }
                  /// @dev Returns if an module is enabled
                  /// @return True if the module is enabled
                  function isModuleEnabled(address module) public view returns (bool) {
                      return SENTINEL_MODULES != module && modules[module] != address(0);
                  }
                  /// @dev Returns array of modules.
                  /// @param start Start of the page.
                  /// @param pageSize Maximum number of modules that should be returned.
                  /// @return array Array of modules.
                  /// @return next Start of the next page.
                  function getModulesPaginated(address start, uint256 pageSize) external view returns (address[] memory array, address next) {
                      // Init array with max page size
                      array = new address[](pageSize);
                      // Populate return array
                      uint256 moduleCount = 0;
                      address currentModule = modules[start];
                      while (currentModule != address(0x0) && currentModule != SENTINEL_MODULES && moduleCount < pageSize) {
                          array[moduleCount] = currentModule;
                          currentModule = modules[currentModule];
                          moduleCount++;
                      }
                      next = currentModule;
                      // Set correct size of returned array
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          mstore(array, moduleCount)
                      }
                  }
              }
              // SPDX-License-Identifier: LGPL-3.0-only
              pragma solidity >=0.7.0 <0.9.0;
              import "../common/SelfAuthorized.sol";
              /// @title OwnerManager - Manages a set of owners and a threshold to perform actions.
              /// @author Stefan George - <stefan@gnosis.pm>
              /// @author Richard Meissner - <richard@gnosis.pm>
              contract OwnerManager is SelfAuthorized {
                  event AddedOwner(address owner);
                  event RemovedOwner(address owner);
                  event ChangedThreshold(uint256 threshold);
                  address internal constant SENTINEL_OWNERS = address(0x1);
                  mapping(address => address) internal owners;
                  uint256 internal ownerCount;
                  uint256 internal threshold;
                  /// @dev Setup function sets initial storage of contract.
                  /// @param _owners List of Safe owners.
                  /// @param _threshold Number of required confirmations for a Safe transaction.
                  function setupOwners(address[] memory _owners, uint256 _threshold) internal {
                      // Threshold can only be 0 at initialization.
                      // Check ensures that setup function can only be called once.
                      require(threshold == 0, "GS200");
                      // Validate that threshold is smaller than number of added owners.
                      require(_threshold <= _owners.length, "GS201");
                      // There has to be at least one Safe owner.
                      require(_threshold >= 1, "GS202");
                      // Initializing Safe owners.
                      address currentOwner = SENTINEL_OWNERS;
                      for (uint256 i = 0; i < _owners.length; i++) {
                          // Owner address cannot be null.
                          address owner = _owners[i];
                          require(owner != address(0) && owner != SENTINEL_OWNERS && owner != address(this) && currentOwner != owner, "GS203");
                          // No duplicate owners allowed.
                          require(owners[owner] == address(0), "GS204");
                          owners[currentOwner] = owner;
                          currentOwner = owner;
                      }
                      owners[currentOwner] = SENTINEL_OWNERS;
                      ownerCount = _owners.length;
                      threshold = _threshold;
                  }
                  /// @dev Allows to add a new owner to the Safe and update the threshold at the same time.
                  ///      This can only be done via a Safe transaction.
                  /// @notice Adds the owner `owner` to the Safe and updates the threshold to `_threshold`.
                  /// @param owner New owner address.
                  /// @param _threshold New threshold.
                  function addOwnerWithThreshold(address owner, uint256 _threshold) public authorized {
                      // Owner address cannot be null, the sentinel or the Safe itself.
                      require(owner != address(0) && owner != SENTINEL_OWNERS && owner != address(this), "GS203");
                      // No duplicate owners allowed.
                      require(owners[owner] == address(0), "GS204");
                      owners[owner] = owners[SENTINEL_OWNERS];
                      owners[SENTINEL_OWNERS] = owner;
                      ownerCount++;
                      emit AddedOwner(owner);
                      // Change threshold if threshold was changed.
                      if (threshold != _threshold) changeThreshold(_threshold);
                  }
                  /// @dev Allows to remove an owner from the Safe and update the threshold at the same time.
                  ///      This can only be done via a Safe transaction.
                  /// @notice Removes the owner `owner` from the Safe and updates the threshold to `_threshold`.
                  /// @param prevOwner Owner that pointed to the owner to be removed in the linked list
                  /// @param owner Owner address to be removed.
                  /// @param _threshold New threshold.
                  function removeOwner(
                      address prevOwner,
                      address owner,
                      uint256 _threshold
                  ) public authorized {
                      // Only allow to remove an owner, if threshold can still be reached.
                      require(ownerCount - 1 >= _threshold, "GS201");
                      // Validate owner address and check that it corresponds to owner index.
                      require(owner != address(0) && owner != SENTINEL_OWNERS, "GS203");
                      require(owners[prevOwner] == owner, "GS205");
                      owners[prevOwner] = owners[owner];
                      owners[owner] = address(0);
                      ownerCount--;
                      emit RemovedOwner(owner);
                      // Change threshold if threshold was changed.
                      if (threshold != _threshold) changeThreshold(_threshold);
                  }
                  /// @dev Allows to swap/replace an owner from the Safe with another address.
                  ///      This can only be done via a Safe transaction.
                  /// @notice Replaces the owner `oldOwner` in the Safe with `newOwner`.
                  /// @param prevOwner Owner that pointed to the owner to be replaced in the linked list
                  /// @param oldOwner Owner address to be replaced.
                  /// @param newOwner New owner address.
                  function swapOwner(
                      address prevOwner,
                      address oldOwner,
                      address newOwner
                  ) public authorized {
                      // Owner address cannot be null, the sentinel or the Safe itself.
                      require(newOwner != address(0) && newOwner != SENTINEL_OWNERS && newOwner != address(this), "GS203");
                      // No duplicate owners allowed.
                      require(owners[newOwner] == address(0), "GS204");
                      // Validate oldOwner address and check that it corresponds to owner index.
                      require(oldOwner != address(0) && oldOwner != SENTINEL_OWNERS, "GS203");
                      require(owners[prevOwner] == oldOwner, "GS205");
                      owners[newOwner] = owners[oldOwner];
                      owners[prevOwner] = newOwner;
                      owners[oldOwner] = address(0);
                      emit RemovedOwner(oldOwner);
                      emit AddedOwner(newOwner);
                  }
                  /// @dev Allows to update the number of required confirmations by Safe owners.
                  ///      This can only be done via a Safe transaction.
                  /// @notice Changes the threshold of the Safe to `_threshold`.
                  /// @param _threshold New threshold.
                  function changeThreshold(uint256 _threshold) public authorized {
                      // Validate that threshold is smaller than number of owners.
                      require(_threshold <= ownerCount, "GS201");
                      // There has to be at least one Safe owner.
                      require(_threshold >= 1, "GS202");
                      threshold = _threshold;
                      emit ChangedThreshold(threshold);
                  }
                  function getThreshold() public view returns (uint256) {
                      return threshold;
                  }
                  function isOwner(address owner) public view returns (bool) {
                      return owner != SENTINEL_OWNERS && owners[owner] != address(0);
                  }
                  /// @dev Returns array of owners.
                  /// @return Array of Safe owners.
                  function getOwners() public view returns (address[] memory) {
                      address[] memory array = new address[](ownerCount);
                      // populate return array
                      uint256 index = 0;
                      address currentOwner = owners[SENTINEL_OWNERS];
                      while (currentOwner != SENTINEL_OWNERS) {
                          array[index] = currentOwner;
                          currentOwner = owners[currentOwner];
                          index++;
                      }
                      return array;
                  }
              }
              // SPDX-License-Identifier: LGPL-3.0-only
              pragma solidity >=0.7.0 <0.9.0;
              /// @title Enum - Collection of enums
              /// @author Richard Meissner - <richard@gnosis.pm>
              contract Enum {
                  enum Operation {Call, DelegateCall}
              }
              // SPDX-License-Identifier: LGPL-3.0-only
              pragma solidity >=0.7.0 <0.9.0;
              /// @title EtherPaymentFallback - A contract that has a fallback to accept ether payments
              /// @author Richard Meissner - <richard@gnosis.pm>
              contract EtherPaymentFallback {
                  event SafeReceived(address indexed sender, uint256 value);
                  /// @dev Fallback function accepts Ether transactions.
                  receive() external payable {
                      emit SafeReceived(msg.sender, msg.value);
                  }
              }
              // SPDX-License-Identifier: LGPL-3.0-only
              pragma solidity >=0.7.0 <0.9.0;
              /// @title SecuredTokenTransfer - Secure token transfer
              /// @author Richard Meissner - <richard@gnosis.pm>
              contract SecuredTokenTransfer {
                  /// @dev Transfers a token and returns if it was a success
                  /// @param token Token that should be transferred
                  /// @param receiver Receiver to whom the token should be transferred
                  /// @param amount The amount of tokens that should be transferred
                  function transferToken(
                      address token,
                      address receiver,
                      uint256 amount
                  ) internal returns (bool transferred) {
                      // 0xa9059cbb - keccack("transfer(address,uint256)")
                      bytes memory data = abi.encodeWithSelector(0xa9059cbb, receiver, amount);
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          // We write the return value to scratch space.
                          // See https://docs.soliditylang.org/en/v0.7.6/internals/layout_in_memory.html#layout-in-memory
                          let success := call(sub(gas(), 10000), token, 0, add(data, 0x20), mload(data), 0, 0x20)
                          switch returndatasize()
                              case 0 {
                                  transferred := success
                              }
                              case 0x20 {
                                  transferred := iszero(or(iszero(success), iszero(mload(0))))
                              }
                              default {
                                  transferred := 0
                              }
                      }
                  }
              }
              // SPDX-License-Identifier: LGPL-3.0-only
              pragma solidity >=0.7.0 <0.9.0;
              /// @title SelfAuthorized - authorizes current contract to perform actions
              /// @author Richard Meissner - <richard@gnosis.pm>
              contract SelfAuthorized {
                  function requireSelfCall() private view {
                      require(msg.sender == address(this), "GS031");
                  }
                  modifier authorized() {
                      // This is a function call as it minimized the bytecode size
                      requireSelfCall();
                      _;
                  }
              }
              // SPDX-License-Identifier: LGPL-3.0-only
              pragma solidity >=0.7.0 <0.9.0;
              /// @title SignatureDecoder - Decodes signatures that a encoded as bytes
              /// @author Richard Meissner - <richard@gnosis.pm>
              contract SignatureDecoder {
                  /// @dev divides bytes signature into `uint8 v, bytes32 r, bytes32 s`.
                  /// @notice Make sure to peform a bounds check for @param pos, to avoid out of bounds access on @param signatures
                  /// @param pos which signature to read. A prior bounds check of this parameter should be performed, to avoid out of bounds access
                  /// @param signatures concatenated rsv signatures
                  function signatureSplit(bytes memory signatures, uint256 pos)
                      internal
                      pure
                      returns (
                          uint8 v,
                          bytes32 r,
                          bytes32 s
                      )
                  {
                      // The signature format is a compact form of:
                      //   {bytes32 r}{bytes32 s}{uint8 v}
                      // Compact means, uint8 is not padded to 32 bytes.
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          let signaturePos := mul(0x41, pos)
                          r := mload(add(signatures, add(signaturePos, 0x20)))
                          s := mload(add(signatures, add(signaturePos, 0x40)))
                          // Here we are loading the last 32 bytes, including 31 bytes
                          // of 's'. There is no 'mload8' to do this.
                          //
                          // 'byte' is not working due to the Solidity parser, so lets
                          // use the second best option, 'and'
                          v := and(mload(add(signatures, add(signaturePos, 0x41))), 0xff)
                      }
                  }
              }
              // SPDX-License-Identifier: LGPL-3.0-only
              pragma solidity >=0.7.0 <0.9.0;
              /// @title Singleton - Base for singleton contracts (should always be first super contract)
              ///         This contract is tightly coupled to our proxy contract (see `proxies/GnosisSafeProxy.sol`)
              /// @author Richard Meissner - <richard@gnosis.io>
              contract Singleton {
                  // singleton always needs to be first declared variable, to ensure that it is at the same location as in the Proxy contract.
                  // It should also always be ensured that the address is stored alone (uses a full word)
                  address private singleton;
              }
              // SPDX-License-Identifier: LGPL-3.0-only
              pragma solidity >=0.7.0 <0.9.0;
              /// @title StorageAccessible - generic base contract that allows callers to access all internal storage.
              /// @notice See https://github.com/gnosis/util-contracts/blob/bb5fe5fb5df6d8400998094fb1b32a178a47c3a1/contracts/StorageAccessible.sol
              contract StorageAccessible {
                  /**
                   * @dev Reads `length` bytes of storage in the currents contract
                   * @param offset - the offset in the current contract's storage in words to start reading from
                   * @param length - the number of words (32 bytes) of data to read
                   * @return the bytes that were read.
                   */
                  function getStorageAt(uint256 offset, uint256 length) public view returns (bytes memory) {
                      bytes memory result = new bytes(length * 32);
                      for (uint256 index = 0; index < length; index++) {
                          // solhint-disable-next-line no-inline-assembly
                          assembly {
                              let word := sload(add(offset, index))
                              mstore(add(add(result, 0x20), mul(index, 0x20)), word)
                          }
                      }
                      return result;
                  }
                  /**
                   * @dev Performs a delegetecall on a targetContract in the context of self.
                   * Internally reverts execution to avoid side effects (making it static).
                   *
                   * This method reverts with data equal to `abi.encode(bool(success), bytes(response))`.
                   * Specifically, the `returndata` after a call to this method will be:
                   * `success:bool || response.length:uint256 || response:bytes`.
                   *
                   * @param targetContract Address of the contract containing the code to execute.
                   * @param calldataPayload Calldata that should be sent to the target contract (encoded method name and arguments).
                   */
                  function simulateAndRevert(address targetContract, bytes memory calldataPayload) external {
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          let success := delegatecall(gas(), targetContract, add(calldataPayload, 0x20), mload(calldataPayload), 0, 0)
                          mstore(0x00, success)
                          mstore(0x20, returndatasize())
                          returndatacopy(0x40, 0, returndatasize())
                          revert(0, add(returndatasize(), 0x40))
                      }
                  }
              }
              // SPDX-License-Identifier: LGPL-3.0-only
              pragma solidity >=0.7.0 <0.9.0;
              /**
               * @title GnosisSafeMath
               * @dev Math operations with safety checks that revert on error
               * Renamed from SafeMath to GnosisSafeMath to avoid conflicts
               * TODO: remove once open zeppelin update to solc 0.5.0
               */
              library GnosisSafeMath {
                  /**
                   * @dev Multiplies two numbers, reverts on overflow.
                   */
                  function mul(uint256 a, uint256 b) internal pure returns (uint256) {
                      // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
                      // benefit is lost if 'b' is also tested.
                      // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
                      if (a == 0) {
                          return 0;
                      }
                      uint256 c = a * b;
                      require(c / a == b);
                      return c;
                  }
                  /**
                   * @dev Subtracts two numbers, reverts on overflow (i.e. if subtrahend is greater than minuend).
                   */
                  function sub(uint256 a, uint256 b) internal pure returns (uint256) {
                      require(b <= a);
                      uint256 c = a - b;
                      return c;
                  }
                  /**
                   * @dev Adds two numbers, reverts on overflow.
                   */
                  function add(uint256 a, uint256 b) internal pure returns (uint256) {
                      uint256 c = a + b;
                      require(c >= a);
                      return c;
                  }
                  /**
                   * @dev Returns the largest of two numbers.
                   */
                  function max(uint256 a, uint256 b) internal pure returns (uint256) {
                      return a >= b ? a : b;
                  }
              }
              // SPDX-License-Identifier: LGPL-3.0-only
              pragma solidity >=0.7.0 <0.9.0;
              contract ISignatureValidatorConstants {
                  // bytes4(keccak256("isValidSignature(bytes,bytes)")
                  bytes4 internal constant EIP1271_MAGIC_VALUE = 0x20c13b0b;
              }
              abstract contract ISignatureValidator is ISignatureValidatorConstants {
                  /**
                   * @dev Should return whether the signature provided is valid for the provided data
                   * @param _data Arbitrary length data signed on the behalf of address(this)
                   * @param _signature Signature byte array associated with _data
                   *
                   * MUST return the bytes4 magic value 0x20c13b0b when function passes.
                   * MUST NOT modify state (using STATICCALL for solc < 0.5, view modifier for solc > 0.5)
                   * MUST allow external calls
                   */
                  function isValidSignature(bytes memory _data, bytes memory _signature) public view virtual returns (bytes4);
              }