ETH Price: $2,133.36 (+0.69%)

Transaction Decoder

Block:
21474140 at Dec-24-2024 06:32:59 PM +UTC
Transaction Fee:
0.001579256475577326 ETH $3.37
Gas Used:
179,046 Gas / 8.820395181 Gwei

Emitted Events:

422 FiatTokenProxy.0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef( 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, 0x0000000000000000000000005de1b7f14de50ed6e430ea144eed8bc9d0bbb30c, 0x0000000000000000000000001de327c23ed8f52f797d55b31abce98cb46c8ea9, 00000000000000000000000000000000000000000000000000000048586caec0 )
423 ExternalRequestsManager.MintRequestCreated( id=699, provider=[Sender] 0x5de1b7f14de50ed6e430ea144eed8bc9d0bbb30c, depositToken=FiatTokenProxy, amount=310721162944, minMintAmount=0 )

Account State Difference:

  Address   Before After State Difference Code
0x1De327C2...cb46C8EA9
(Titan Builder)
12.079881592880235364 Eth12.079890545180235364 Eth0.0000089523
0x5dE1B7f1...9d0Bbb30C
0.044029826643238341 Eth
Nonce: 536
0.042450570167661015 Eth
Nonce: 537
0.001579256475577326
0xA0b86991...E3606eB48

Execution Trace

ExternalRequestsManager.requestMint( _depositTokenAddress=0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48, _amount=310721162944, _minMintAmount=0 )
  • AddressesWhitelist.isAllowedAccount( _account=0x5dE1B7f14De50Ed6e430ea144eED8Bc9d0Bbb30C ) => ( isAllowed=True )
  • FiatTokenProxy.23b872dd( )
    • FiatTokenV2_2.transferFrom( from=0x5dE1B7f14De50Ed6e430ea144eED8Bc9d0Bbb30C, to=0x1De327C23ed8F52f797D55B31ABCe98cb46C8EA9, value=310721162944 ) => ( True )
      File 1 of 4: ExternalRequestsManager
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v5.0.0) (access/AccessControl.sol)
      pragma solidity ^0.8.20;
      import {IAccessControl} from "./IAccessControl.sol";
      import {Context} from "../utils/Context.sol";
      import {ERC165} from "../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:
       *
       * ```solidity
       * 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}:
       *
       * ```solidity
       * 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. We recommend using {AccessControlDefaultAdminRules}
       * to enforce additional security measures for this role.
       */
      abstract contract AccessControl is Context, IAccessControl, ERC165 {
          struct RoleData {
              mapping(address account => bool) hasRole;
              bytes32 adminRole;
          }
          mapping(bytes32 role => RoleData) private _roles;
          bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;
          /**
           * @dev Modifier that checks that an account has a specific role. Reverts
           * with an {AccessControlUnauthorizedAccount} error including the required role.
           */
          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 returns (bool) {
              return _roles[role].hasRole[account];
          }
          /**
           * @dev Reverts with an {AccessControlUnauthorizedAccount} error if `_msgSender()`
           * is missing `role`. Overriding this function changes the behavior of the {onlyRole} modifier.
           */
          function _checkRole(bytes32 role) internal view virtual {
              _checkRole(role, _msgSender());
          }
          /**
           * @dev Reverts with an {AccessControlUnauthorizedAccount} error if `account`
           * is missing `role`.
           */
          function _checkRole(bytes32 role, address account) internal view virtual {
              if (!hasRole(role, account)) {
                  revert AccessControlUnauthorizedAccount(account, role);
              }
          }
          /**
           * @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 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.
           *
           * May emit a {RoleGranted} event.
           */
          function grantRole(bytes32 role, address account) public virtual 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.
           *
           * May emit a {RoleRevoked} event.
           */
          function revokeRole(bytes32 role, address account) public virtual 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 `callerConfirmation`.
           *
           * May emit a {RoleRevoked} event.
           */
          function renounceRole(bytes32 role, address callerConfirmation) public virtual {
              if (callerConfirmation != _msgSender()) {
                  revert AccessControlBadConfirmation();
              }
              _revokeRole(role, callerConfirmation);
          }
          /**
           * @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 Attempts to grant `role` to `account` and returns a boolean indicating if `role` was granted.
           *
           * Internal function without access restriction.
           *
           * May emit a {RoleGranted} event.
           */
          function _grantRole(bytes32 role, address account) internal virtual returns (bool) {
              if (!hasRole(role, account)) {
                  _roles[role].hasRole[account] = true;
                  emit RoleGranted(role, account, _msgSender());
                  return true;
              } else {
                  return false;
              }
          }
          /**
           * @dev Attempts to revoke `role` to `account` and returns a boolean indicating if `role` was revoked.
           *
           * Internal function without access restriction.
           *
           * May emit a {RoleRevoked} event.
           */
          function _revokeRole(bytes32 role, address account) internal virtual returns (bool) {
              if (hasRole(role, account)) {
                  _roles[role].hasRole[account] = false;
                  emit RoleRevoked(role, account, _msgSender());
                  return true;
              } else {
                  return false;
              }
          }
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v5.0.0) (access/extensions/AccessControlDefaultAdminRules.sol)
      pragma solidity ^0.8.20;
      import {IAccessControlDefaultAdminRules} from "./IAccessControlDefaultAdminRules.sol";
      import {AccessControl, IAccessControl} from "../AccessControl.sol";
      import {SafeCast} from "../../utils/math/SafeCast.sol";
      import {Math} from "../../utils/math/Math.sol";
      import {IERC5313} from "../../interfaces/IERC5313.sol";
      /**
       * @dev Extension of {AccessControl} that allows specifying special rules to manage
       * the `DEFAULT_ADMIN_ROLE` holder, which is a sensitive role with special permissions
       * over other roles that may potentially have privileged rights in the system.
       *
       * If a specific role doesn't have an admin role assigned, the holder of the
       * `DEFAULT_ADMIN_ROLE` will have the ability to grant it and revoke it.
       *
       * This contract implements the following risk mitigations on top of {AccessControl}:
       *
       * * Only one account holds the `DEFAULT_ADMIN_ROLE` since deployment until it's potentially renounced.
       * * Enforces a 2-step process to transfer the `DEFAULT_ADMIN_ROLE` to another account.
       * * Enforces a configurable delay between the two steps, with the ability to cancel before the transfer is accepted.
       * * The delay can be changed by scheduling, see {changeDefaultAdminDelay}.
       * * It is not possible to use another role to manage the `DEFAULT_ADMIN_ROLE`.
       *
       * Example usage:
       *
       * ```solidity
       * contract MyToken is AccessControlDefaultAdminRules {
       *   constructor() AccessControlDefaultAdminRules(
       *     3 days,
       *     msg.sender // Explicit initial `DEFAULT_ADMIN_ROLE` holder
       *    ) {}
       * }
       * ```
       */
      abstract contract AccessControlDefaultAdminRules is IAccessControlDefaultAdminRules, IERC5313, AccessControl {
          // pending admin pair read/written together frequently
          address private _pendingDefaultAdmin;
          uint48 private _pendingDefaultAdminSchedule; // 0 == unset
          uint48 private _currentDelay;
          address private _currentDefaultAdmin;
          // pending delay pair read/written together frequently
          uint48 private _pendingDelay;
          uint48 private _pendingDelaySchedule; // 0 == unset
          /**
           * @dev Sets the initial values for {defaultAdminDelay} and {defaultAdmin} address.
           */
          constructor(uint48 initialDelay, address initialDefaultAdmin) {
              if (initialDefaultAdmin == address(0)) {
                  revert AccessControlInvalidDefaultAdmin(address(0));
              }
              _currentDelay = initialDelay;
              _grantRole(DEFAULT_ADMIN_ROLE, initialDefaultAdmin);
          }
          /**
           * @dev See {IERC165-supportsInterface}.
           */
          function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
              return interfaceId == type(IAccessControlDefaultAdminRules).interfaceId || super.supportsInterface(interfaceId);
          }
          /**
           * @dev See {IERC5313-owner}.
           */
          function owner() public view virtual returns (address) {
              return defaultAdmin();
          }
          ///
          /// Override AccessControl role management
          ///
          /**
           * @dev See {AccessControl-grantRole}. Reverts for `DEFAULT_ADMIN_ROLE`.
           */
          function grantRole(bytes32 role, address account) public virtual override(AccessControl, IAccessControl) {
              if (role == DEFAULT_ADMIN_ROLE) {
                  revert AccessControlEnforcedDefaultAdminRules();
              }
              super.grantRole(role, account);
          }
          /**
           * @dev See {AccessControl-revokeRole}. Reverts for `DEFAULT_ADMIN_ROLE`.
           */
          function revokeRole(bytes32 role, address account) public virtual override(AccessControl, IAccessControl) {
              if (role == DEFAULT_ADMIN_ROLE) {
                  revert AccessControlEnforcedDefaultAdminRules();
              }
              super.revokeRole(role, account);
          }
          /**
           * @dev See {AccessControl-renounceRole}.
           *
           * For the `DEFAULT_ADMIN_ROLE`, it only allows renouncing in two steps by first calling
           * {beginDefaultAdminTransfer} to the `address(0)`, so it's required that the {pendingDefaultAdmin} schedule
           * has also passed when calling this function.
           *
           * After its execution, it will not be possible to call `onlyRole(DEFAULT_ADMIN_ROLE)` functions.
           *
           * NOTE: Renouncing `DEFAULT_ADMIN_ROLE` will leave the contract without a {defaultAdmin},
           * thereby disabling any functionality that is only available for it, and the possibility of reassigning a
           * non-administrated role.
           */
          function renounceRole(bytes32 role, address account) public virtual override(AccessControl, IAccessControl) {
              if (role == DEFAULT_ADMIN_ROLE && account == defaultAdmin()) {
                  (address newDefaultAdmin, uint48 schedule) = pendingDefaultAdmin();
                  if (newDefaultAdmin != address(0) || !_isScheduleSet(schedule) || !_hasSchedulePassed(schedule)) {
                      revert AccessControlEnforcedDefaultAdminDelay(schedule);
                  }
                  delete _pendingDefaultAdminSchedule;
              }
              super.renounceRole(role, account);
          }
          /**
           * @dev See {AccessControl-_grantRole}.
           *
           * For `DEFAULT_ADMIN_ROLE`, it only allows granting if there isn't already a {defaultAdmin} or if the
           * role has been previously renounced.
           *
           * NOTE: Exposing this function through another mechanism may make the `DEFAULT_ADMIN_ROLE`
           * assignable again. Make sure to guarantee this is the expected behavior in your implementation.
           */
          function _grantRole(bytes32 role, address account) internal virtual override returns (bool) {
              if (role == DEFAULT_ADMIN_ROLE) {
                  if (defaultAdmin() != address(0)) {
                      revert AccessControlEnforcedDefaultAdminRules();
                  }
                  _currentDefaultAdmin = account;
              }
              return super._grantRole(role, account);
          }
          /**
           * @dev See {AccessControl-_revokeRole}.
           */
          function _revokeRole(bytes32 role, address account) internal virtual override returns (bool) {
              if (role == DEFAULT_ADMIN_ROLE && account == defaultAdmin()) {
                  delete _currentDefaultAdmin;
              }
              return super._revokeRole(role, account);
          }
          /**
           * @dev See {AccessControl-_setRoleAdmin}. Reverts for `DEFAULT_ADMIN_ROLE`.
           */
          function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual override {
              if (role == DEFAULT_ADMIN_ROLE) {
                  revert AccessControlEnforcedDefaultAdminRules();
              }
              super._setRoleAdmin(role, adminRole);
          }
          ///
          /// AccessControlDefaultAdminRules accessors
          ///
          /**
           * @inheritdoc IAccessControlDefaultAdminRules
           */
          function defaultAdmin() public view virtual returns (address) {
              return _currentDefaultAdmin;
          }
          /**
           * @inheritdoc IAccessControlDefaultAdminRules
           */
          function pendingDefaultAdmin() public view virtual returns (address newAdmin, uint48 schedule) {
              return (_pendingDefaultAdmin, _pendingDefaultAdminSchedule);
          }
          /**
           * @inheritdoc IAccessControlDefaultAdminRules
           */
          function defaultAdminDelay() public view virtual returns (uint48) {
              uint48 schedule = _pendingDelaySchedule;
              return (_isScheduleSet(schedule) && _hasSchedulePassed(schedule)) ? _pendingDelay : _currentDelay;
          }
          /**
           * @inheritdoc IAccessControlDefaultAdminRules
           */
          function pendingDefaultAdminDelay() public view virtual returns (uint48 newDelay, uint48 schedule) {
              schedule = _pendingDelaySchedule;
              return (_isScheduleSet(schedule) && !_hasSchedulePassed(schedule)) ? (_pendingDelay, schedule) : (0, 0);
          }
          /**
           * @inheritdoc IAccessControlDefaultAdminRules
           */
          function defaultAdminDelayIncreaseWait() public view virtual returns (uint48) {
              return 5 days;
          }
          ///
          /// AccessControlDefaultAdminRules public and internal setters for defaultAdmin/pendingDefaultAdmin
          ///
          /**
           * @inheritdoc IAccessControlDefaultAdminRules
           */
          function beginDefaultAdminTransfer(address newAdmin) public virtual onlyRole(DEFAULT_ADMIN_ROLE) {
              _beginDefaultAdminTransfer(newAdmin);
          }
          /**
           * @dev See {beginDefaultAdminTransfer}.
           *
           * Internal function without access restriction.
           */
          function _beginDefaultAdminTransfer(address newAdmin) internal virtual {
              uint48 newSchedule = SafeCast.toUint48(block.timestamp) + defaultAdminDelay();
              _setPendingDefaultAdmin(newAdmin, newSchedule);
              emit DefaultAdminTransferScheduled(newAdmin, newSchedule);
          }
          /**
           * @inheritdoc IAccessControlDefaultAdminRules
           */
          function cancelDefaultAdminTransfer() public virtual onlyRole(DEFAULT_ADMIN_ROLE) {
              _cancelDefaultAdminTransfer();
          }
          /**
           * @dev See {cancelDefaultAdminTransfer}.
           *
           * Internal function without access restriction.
           */
          function _cancelDefaultAdminTransfer() internal virtual {
              _setPendingDefaultAdmin(address(0), 0);
          }
          /**
           * @inheritdoc IAccessControlDefaultAdminRules
           */
          function acceptDefaultAdminTransfer() public virtual {
              (address newDefaultAdmin, ) = pendingDefaultAdmin();
              if (_msgSender() != newDefaultAdmin) {
                  // Enforce newDefaultAdmin explicit acceptance.
                  revert AccessControlInvalidDefaultAdmin(_msgSender());
              }
              _acceptDefaultAdminTransfer();
          }
          /**
           * @dev See {acceptDefaultAdminTransfer}.
           *
           * Internal function without access restriction.
           */
          function _acceptDefaultAdminTransfer() internal virtual {
              (address newAdmin, uint48 schedule) = pendingDefaultAdmin();
              if (!_isScheduleSet(schedule) || !_hasSchedulePassed(schedule)) {
                  revert AccessControlEnforcedDefaultAdminDelay(schedule);
              }
              _revokeRole(DEFAULT_ADMIN_ROLE, defaultAdmin());
              _grantRole(DEFAULT_ADMIN_ROLE, newAdmin);
              delete _pendingDefaultAdmin;
              delete _pendingDefaultAdminSchedule;
          }
          ///
          /// AccessControlDefaultAdminRules public and internal setters for defaultAdminDelay/pendingDefaultAdminDelay
          ///
          /**
           * @inheritdoc IAccessControlDefaultAdminRules
           */
          function changeDefaultAdminDelay(uint48 newDelay) public virtual onlyRole(DEFAULT_ADMIN_ROLE) {
              _changeDefaultAdminDelay(newDelay);
          }
          /**
           * @dev See {changeDefaultAdminDelay}.
           *
           * Internal function without access restriction.
           */
          function _changeDefaultAdminDelay(uint48 newDelay) internal virtual {
              uint48 newSchedule = SafeCast.toUint48(block.timestamp) + _delayChangeWait(newDelay);
              _setPendingDelay(newDelay, newSchedule);
              emit DefaultAdminDelayChangeScheduled(newDelay, newSchedule);
          }
          /**
           * @inheritdoc IAccessControlDefaultAdminRules
           */
          function rollbackDefaultAdminDelay() public virtual onlyRole(DEFAULT_ADMIN_ROLE) {
              _rollbackDefaultAdminDelay();
          }
          /**
           * @dev See {rollbackDefaultAdminDelay}.
           *
           * Internal function without access restriction.
           */
          function _rollbackDefaultAdminDelay() internal virtual {
              _setPendingDelay(0, 0);
          }
          /**
           * @dev Returns the amount of seconds to wait after the `newDelay` will
           * become the new {defaultAdminDelay}.
           *
           * The value returned guarantees that if the delay is reduced, it will go into effect
           * after a wait that honors the previously set delay.
           *
           * See {defaultAdminDelayIncreaseWait}.
           */
          function _delayChangeWait(uint48 newDelay) internal view virtual returns (uint48) {
              uint48 currentDelay = defaultAdminDelay();
              // When increasing the delay, we schedule the delay change to occur after a period of "new delay" has passed, up
              // to a maximum given by defaultAdminDelayIncreaseWait, by default 5 days. For example, if increasing from 1 day
              // to 3 days, the new delay will come into effect after 3 days. If increasing from 1 day to 10 days, the new
              // delay will come into effect after 5 days. The 5 day wait period is intended to be able to fix an error like
              // using milliseconds instead of seconds.
              //
              // When decreasing the delay, we wait the difference between "current delay" and "new delay". This guarantees
              // that an admin transfer cannot be made faster than "current delay" at the time the delay change is scheduled.
              // For example, if decreasing from 10 days to 3 days, the new delay will come into effect after 7 days.
              return
                  newDelay > currentDelay
                      ? uint48(Math.min(newDelay, defaultAdminDelayIncreaseWait())) // no need to safecast, both inputs are uint48
                      : currentDelay - newDelay;
          }
          ///
          /// Private setters
          ///
          /**
           * @dev Setter of the tuple for pending admin and its schedule.
           *
           * May emit a DefaultAdminTransferCanceled event.
           */
          function _setPendingDefaultAdmin(address newAdmin, uint48 newSchedule) private {
              (, uint48 oldSchedule) = pendingDefaultAdmin();
              _pendingDefaultAdmin = newAdmin;
              _pendingDefaultAdminSchedule = newSchedule;
              // An `oldSchedule` from `pendingDefaultAdmin()` is only set if it hasn't been accepted.
              if (_isScheduleSet(oldSchedule)) {
                  // Emit for implicit cancellations when another default admin was scheduled.
                  emit DefaultAdminTransferCanceled();
              }
          }
          /**
           * @dev Setter of the tuple for pending delay and its schedule.
           *
           * May emit a DefaultAdminDelayChangeCanceled event.
           */
          function _setPendingDelay(uint48 newDelay, uint48 newSchedule) private {
              uint48 oldSchedule = _pendingDelaySchedule;
              if (_isScheduleSet(oldSchedule)) {
                  if (_hasSchedulePassed(oldSchedule)) {
                      // Materialize a virtual delay
                      _currentDelay = _pendingDelay;
                  } else {
                      // Emit for implicit cancellations when another delay was scheduled.
                      emit DefaultAdminDelayChangeCanceled();
                  }
              }
              _pendingDelay = newDelay;
              _pendingDelaySchedule = newSchedule;
          }
          ///
          /// Private helpers
          ///
          /**
           * @dev Defines if an `schedule` is considered set. For consistency purposes.
           */
          function _isScheduleSet(uint48 schedule) private pure returns (bool) {
              return schedule != 0;
          }
          /**
           * @dev Defines if an `schedule` is considered passed. For consistency purposes.
           */
          function _hasSchedulePassed(uint48 schedule) private view returns (bool) {
              return schedule < block.timestamp;
          }
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v5.0.0) (access/extensions/IAccessControlDefaultAdminRules.sol)
      pragma solidity ^0.8.20;
      import {IAccessControl} from "../IAccessControl.sol";
      /**
       * @dev External interface of AccessControlDefaultAdminRules declared to support ERC165 detection.
       */
      interface IAccessControlDefaultAdminRules is IAccessControl {
          /**
           * @dev The new default admin is not a valid default admin.
           */
          error AccessControlInvalidDefaultAdmin(address defaultAdmin);
          /**
           * @dev At least one of the following rules was violated:
           *
           * - The `DEFAULT_ADMIN_ROLE` must only be managed by itself.
           * - The `DEFAULT_ADMIN_ROLE` must only be held by one account at the time.
           * - Any `DEFAULT_ADMIN_ROLE` transfer must be in two delayed steps.
           */
          error AccessControlEnforcedDefaultAdminRules();
          /**
           * @dev The delay for transferring the default admin delay is enforced and
           * the operation must wait until `schedule`.
           *
           * NOTE: `schedule` can be 0 indicating there's no transfer scheduled.
           */
          error AccessControlEnforcedDefaultAdminDelay(uint48 schedule);
          /**
           * @dev Emitted when a {defaultAdmin} transfer is started, setting `newAdmin` as the next
           * address to become the {defaultAdmin} by calling {acceptDefaultAdminTransfer} only after `acceptSchedule`
           * passes.
           */
          event DefaultAdminTransferScheduled(address indexed newAdmin, uint48 acceptSchedule);
          /**
           * @dev Emitted when a {pendingDefaultAdmin} is reset if it was never accepted, regardless of its schedule.
           */
          event DefaultAdminTransferCanceled();
          /**
           * @dev Emitted when a {defaultAdminDelay} change is started, setting `newDelay` as the next
           * delay to be applied between default admin transfer after `effectSchedule` has passed.
           */
          event DefaultAdminDelayChangeScheduled(uint48 newDelay, uint48 effectSchedule);
          /**
           * @dev Emitted when a {pendingDefaultAdminDelay} is reset if its schedule didn't pass.
           */
          event DefaultAdminDelayChangeCanceled();
          /**
           * @dev Returns the address of the current `DEFAULT_ADMIN_ROLE` holder.
           */
          function defaultAdmin() external view returns (address);
          /**
           * @dev Returns a tuple of a `newAdmin` and an accept schedule.
           *
           * After the `schedule` passes, the `newAdmin` will be able to accept the {defaultAdmin} role
           * by calling {acceptDefaultAdminTransfer}, completing the role transfer.
           *
           * A zero value only in `acceptSchedule` indicates no pending admin transfer.
           *
           * NOTE: A zero address `newAdmin` means that {defaultAdmin} is being renounced.
           */
          function pendingDefaultAdmin() external view returns (address newAdmin, uint48 acceptSchedule);
          /**
           * @dev Returns the delay required to schedule the acceptance of a {defaultAdmin} transfer started.
           *
           * This delay will be added to the current timestamp when calling {beginDefaultAdminTransfer} to set
           * the acceptance schedule.
           *
           * NOTE: If a delay change has been scheduled, it will take effect as soon as the schedule passes, making this
           * function returns the new delay. See {changeDefaultAdminDelay}.
           */
          function defaultAdminDelay() external view returns (uint48);
          /**
           * @dev Returns a tuple of `newDelay` and an effect schedule.
           *
           * After the `schedule` passes, the `newDelay` will get into effect immediately for every
           * new {defaultAdmin} transfer started with {beginDefaultAdminTransfer}.
           *
           * A zero value only in `effectSchedule` indicates no pending delay change.
           *
           * NOTE: A zero value only for `newDelay` means that the next {defaultAdminDelay}
           * will be zero after the effect schedule.
           */
          function pendingDefaultAdminDelay() external view returns (uint48 newDelay, uint48 effectSchedule);
          /**
           * @dev Starts a {defaultAdmin} transfer by setting a {pendingDefaultAdmin} scheduled for acceptance
           * after the current timestamp plus a {defaultAdminDelay}.
           *
           * Requirements:
           *
           * - Only can be called by the current {defaultAdmin}.
           *
           * Emits a DefaultAdminRoleChangeStarted event.
           */
          function beginDefaultAdminTransfer(address newAdmin) external;
          /**
           * @dev Cancels a {defaultAdmin} transfer previously started with {beginDefaultAdminTransfer}.
           *
           * A {pendingDefaultAdmin} not yet accepted can also be cancelled with this function.
           *
           * Requirements:
           *
           * - Only can be called by the current {defaultAdmin}.
           *
           * May emit a DefaultAdminTransferCanceled event.
           */
          function cancelDefaultAdminTransfer() external;
          /**
           * @dev Completes a {defaultAdmin} transfer previously started with {beginDefaultAdminTransfer}.
           *
           * After calling the function:
           *
           * - `DEFAULT_ADMIN_ROLE` should be granted to the caller.
           * - `DEFAULT_ADMIN_ROLE` should be revoked from the previous holder.
           * - {pendingDefaultAdmin} should be reset to zero values.
           *
           * Requirements:
           *
           * - Only can be called by the {pendingDefaultAdmin}'s `newAdmin`.
           * - The {pendingDefaultAdmin}'s `acceptSchedule` should've passed.
           */
          function acceptDefaultAdminTransfer() external;
          /**
           * @dev Initiates a {defaultAdminDelay} update by setting a {pendingDefaultAdminDelay} scheduled for getting
           * into effect after the current timestamp plus a {defaultAdminDelay}.
           *
           * This function guarantees that any call to {beginDefaultAdminTransfer} done between the timestamp this
           * method is called and the {pendingDefaultAdminDelay} effect schedule will use the current {defaultAdminDelay}
           * set before calling.
           *
           * The {pendingDefaultAdminDelay}'s effect schedule is defined in a way that waiting until the schedule and then
           * calling {beginDefaultAdminTransfer} with the new delay will take at least the same as another {defaultAdmin}
           * complete transfer (including acceptance).
           *
           * The schedule is designed for two scenarios:
           *
           * - When the delay is changed for a larger one the schedule is `block.timestamp + newDelay` capped by
           * {defaultAdminDelayIncreaseWait}.
           * - When the delay is changed for a shorter one, the schedule is `block.timestamp + (current delay - new delay)`.
           *
           * A {pendingDefaultAdminDelay} that never got into effect will be canceled in favor of a new scheduled change.
           *
           * Requirements:
           *
           * - Only can be called by the current {defaultAdmin}.
           *
           * Emits a DefaultAdminDelayChangeScheduled event and may emit a DefaultAdminDelayChangeCanceled event.
           */
          function changeDefaultAdminDelay(uint48 newDelay) external;
          /**
           * @dev Cancels a scheduled {defaultAdminDelay} change.
           *
           * Requirements:
           *
           * - Only can be called by the current {defaultAdmin}.
           *
           * May emit a DefaultAdminDelayChangeCanceled event.
           */
          function rollbackDefaultAdminDelay() external;
          /**
           * @dev Maximum time in seconds for an increase to {defaultAdminDelay} (that is scheduled using {changeDefaultAdminDelay})
           * to take effect. Default to 5 days.
           *
           * When the {defaultAdminDelay} is scheduled to be increased, it goes into effect after the new delay has passed with
           * the purpose of giving enough time for reverting any accidental change (i.e. using milliseconds instead of seconds)
           * that may lock the contract. However, to avoid excessive schedules, the wait is capped by this function and it can
           * be overrode for a custom {defaultAdminDelay} increase scheduling.
           *
           * IMPORTANT: Make sure to add a reasonable amount of time while overriding this value, otherwise,
           * there's a risk of setting a high new delay that goes into effect almost immediately without the
           * possibility of human intervention in the case of an input error (eg. set milliseconds instead of seconds).
           */
          function defaultAdminDelayIncreaseWait() external view returns (uint48);
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v5.0.0) (access/IAccessControl.sol)
      pragma solidity ^0.8.20;
      /**
       * @dev External interface of AccessControl declared to support ERC165 detection.
       */
      interface IAccessControl {
          /**
           * @dev The `account` is missing a role.
           */
          error AccessControlUnauthorizedAccount(address account, bytes32 neededRole);
          /**
           * @dev The caller of a function is not the expected one.
           *
           * NOTE: Don't confuse with {AccessControlUnauthorizedAccount}.
           */
          error AccessControlBadConfirmation();
          /**
           * @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.
           */
          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 `callerConfirmation`.
           */
          function renounceRole(bytes32 role, address callerConfirmation) external;
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v5.0.0) (interfaces/IERC5313.sol)
      pragma solidity ^0.8.20;
      /**
       * @dev Interface for the Light Contract Ownership Standard.
       *
       * A standardized minimal interface required to identify an account that controls a contract
       */
      interface IERC5313 {
          /**
           * @dev Gets the address of the owner.
           */
          function owner() external view returns (address);
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/extensions/IERC20Permit.sol)
      pragma solidity ^0.8.20;
      /**
       * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
       * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
       *
       * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
       * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
       * need to send a transaction, and thus is not required to hold Ether at all.
       *
       * ==== Security Considerations
       *
       * There are two important considerations concerning the use of `permit`. The first is that a valid permit signature
       * expresses an allowance, and it should not be assumed to convey additional meaning. In particular, it should not be
       * considered as an intention to spend the allowance in any specific way. The second is that because permits have
       * built-in replay protection and can be submitted by anyone, they can be frontrun. A protocol that uses permits should
       * take this into consideration and allow a `permit` call to fail. Combining these two aspects, a pattern that may be
       * generally recommended is:
       *
       * ```solidity
       * function doThingWithPermit(..., uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) public {
       *     try token.permit(msg.sender, address(this), value, deadline, v, r, s) {} catch {}
       *     doThing(..., value);
       * }
       *
       * function doThing(..., uint256 value) public {
       *     token.safeTransferFrom(msg.sender, address(this), value);
       *     ...
       * }
       * ```
       *
       * Observe that: 1) `msg.sender` is used as the owner, leaving no ambiguity as to the signer intent, and 2) the use of
       * `try/catch` allows the permit to fail and makes the code tolerant to frontrunning. (See also
       * {SafeERC20-safeTransferFrom}).
       *
       * Additionally, note that smart contract wallets (such as Argent or Safe) are not able to produce permit signatures, so
       * contracts should have entry points that don't rely on permit.
       */
      interface IERC20Permit {
          /**
           * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
           * given ``owner``'s signed approval.
           *
           * IMPORTANT: The same issues {IERC20-approve} has related to transaction
           * ordering also apply here.
           *
           * Emits an {Approval} event.
           *
           * Requirements:
           *
           * - `spender` cannot be the zero address.
           * - `deadline` must be a timestamp in the future.
           * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
           * over the EIP712-formatted function arguments.
           * - the signature must use ``owner``'s current nonce (see {nonces}).
           *
           * For more information on the signature format, see the
           * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
           * section].
           *
           * CAUTION: See Security Considerations above.
           */
          function permit(
              address owner,
              address spender,
              uint256 value,
              uint256 deadline,
              uint8 v,
              bytes32 r,
              bytes32 s
          ) external;
          /**
           * @dev Returns the current nonce for `owner`. This value must be
           * included whenever a signature is generated for {permit}.
           *
           * Every successful call to {permit} increases ``owner``'s nonce by one. This
           * prevents a signature from being used multiple times.
           */
          function nonces(address owner) external view returns (uint256);
          /**
           * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
           */
          // solhint-disable-next-line func-name-mixedcase
          function DOMAIN_SEPARATOR() external view returns (bytes32);
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/IERC20.sol)
      pragma solidity ^0.8.20;
      /**
       * @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 value of tokens in existence.
           */
          function totalSupply() external view returns (uint256);
          /**
           * @dev Returns the value of tokens owned by `account`.
           */
          function balanceOf(address account) external view returns (uint256);
          /**
           * @dev Moves a `value` amount of 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 value) 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 a `value` amount of tokens 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 value) external returns (bool);
          /**
           * @dev Moves a `value` amount of tokens from `from` to `to` using the
           * allowance mechanism. `value` 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 value) external returns (bool);
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/utils/SafeERC20.sol)
      pragma solidity ^0.8.20;
      import {IERC20} from "../IERC20.sol";
      import {IERC20Permit} from "../extensions/IERC20Permit.sol";
      import {Address} from "../../../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;
          /**
           * @dev An operation with an ERC20 token failed.
           */
          error SafeERC20FailedOperation(address token);
          /**
           * @dev Indicates a failed `decreaseAllowance` request.
           */
          error SafeERC20FailedDecreaseAllowance(address spender, uint256 currentAllowance, uint256 requestedDecrease);
          /**
           * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
           * non-reverting calls are assumed to be successful.
           */
          function safeTransfer(IERC20 token, address to, uint256 value) internal {
              _callOptionalReturn(token, abi.encodeCall(token.transfer, (to, value)));
          }
          /**
           * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
           * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
           */
          function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
              _callOptionalReturn(token, abi.encodeCall(token.transferFrom, (from, to, value)));
          }
          /**
           * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
           * non-reverting calls are assumed to be successful.
           */
          function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
              uint256 oldAllowance = token.allowance(address(this), spender);
              forceApprove(token, spender, oldAllowance + value);
          }
          /**
           * @dev Decrease the calling contract's allowance toward `spender` by `requestedDecrease`. If `token` returns no
           * value, non-reverting calls are assumed to be successful.
           */
          function safeDecreaseAllowance(IERC20 token, address spender, uint256 requestedDecrease) internal {
              unchecked {
                  uint256 currentAllowance = token.allowance(address(this), spender);
                  if (currentAllowance < requestedDecrease) {
                      revert SafeERC20FailedDecreaseAllowance(spender, currentAllowance, requestedDecrease);
                  }
                  forceApprove(token, spender, currentAllowance - requestedDecrease);
              }
          }
          /**
           * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
           * non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
           * to be set to zero before setting it to a non-zero value, such as USDT.
           */
          function forceApprove(IERC20 token, address spender, uint256 value) internal {
              bytes memory approvalCall = abi.encodeCall(token.approve, (spender, value));
              if (!_callOptionalReturnBool(token, approvalCall)) {
                  _callOptionalReturn(token, abi.encodeCall(token.approve, (spender, 0)));
                  _callOptionalReturn(token, approvalCall);
              }
          }
          /**
           * @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);
              if (returndata.length != 0 && !abi.decode(returndata, (bool))) {
                  revert SafeERC20FailedOperation(address(token));
              }
          }
          /**
           * @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).
           *
           * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
           */
          function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
              // 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 cannot use {Address-functionCall} here since this should return false
              // and not revert is the subcall reverts.
              (bool success, bytes memory returndata) = address(token).call(data);
              return success && (returndata.length == 0 || abi.decode(returndata, (bool))) && address(token).code.length > 0;
          }
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v5.0.0) (utils/Address.sol)
      pragma solidity ^0.8.20;
      /**
       * @dev Collection of functions related to the address type
       */
      library Address {
          /**
           * @dev The ETH balance of the account is not enough to perform the operation.
           */
          error AddressInsufficientBalance(address account);
          /**
           * @dev There's no code at `target` (it is not a contract).
           */
          error AddressEmptyCode(address target);
          /**
           * @dev A call to an address target failed. The target may have reverted.
           */
          error FailedInnerCall();
          /**
           * @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://consensys.net/diligence/blog/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/v0.8.20/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
           */
          function sendValue(address payable recipient, uint256 amount) internal {
              if (address(this).balance < amount) {
                  revert AddressInsufficientBalance(address(this));
              }
              (bool success, ) = recipient.call{value: amount}("");
              if (!success) {
                  revert FailedInnerCall();
              }
          }
          /**
           * @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 or custom error, it is bubbled
           * up by this function (like regular Solidity function calls). However, if
           * the call reverted with no returned reason, this function reverts with a
           * {FailedInnerCall} error.
           *
           * 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.
           */
          function functionCall(address target, bytes memory data) internal returns (bytes memory) {
              return functionCallWithValue(target, data, 0);
          }
          /**
           * @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`.
           */
          function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
              if (address(this).balance < value) {
                  revert AddressInsufficientBalance(address(this));
              }
              (bool success, bytes memory returndata) = target.call{value: value}(data);
              return verifyCallResultFromTarget(target, success, returndata);
          }
          /**
           * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
           * but performing a static call.
           */
          function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
              (bool success, bytes memory returndata) = target.staticcall(data);
              return verifyCallResultFromTarget(target, success, returndata);
          }
          /**
           * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
           * but performing a delegate call.
           */
          function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
              (bool success, bytes memory returndata) = target.delegatecall(data);
              return verifyCallResultFromTarget(target, success, returndata);
          }
          /**
           * @dev Tool to verify that a low level call to smart-contract was successful, and reverts if the target
           * was not a contract or bubbling up the revert reason (falling back to {FailedInnerCall}) in case of an
           * unsuccessful call.
           */
          function verifyCallResultFromTarget(
              address target,
              bool success,
              bytes memory returndata
          ) internal view returns (bytes memory) {
              if (!success) {
                  _revert(returndata);
              } else {
                  // only check if target is a contract if the call was successful and the return data is empty
                  // otherwise we already know that it was a contract
                  if (returndata.length == 0 && target.code.length == 0) {
                      revert AddressEmptyCode(target);
                  }
                  return returndata;
              }
          }
          /**
           * @dev Tool to verify that a low level call was successful, and reverts if it wasn't, either by bubbling the
           * revert reason or with a default {FailedInnerCall} error.
           */
          function verifyCallResult(bool success, bytes memory returndata) internal pure returns (bytes memory) {
              if (!success) {
                  _revert(returndata);
              } else {
                  return returndata;
              }
          }
          /**
           * @dev Reverts with returndata if present. Otherwise reverts with {FailedInnerCall}.
           */
          function _revert(bytes memory returndata) private pure {
              // 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
                  /// @solidity memory-safe-assembly
                  assembly {
                      let returndata_size := mload(returndata)
                      revert(add(32, returndata), returndata_size)
                  }
              } else {
                  revert FailedInnerCall();
              }
          }
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v5.0.1) (utils/Context.sol)
      pragma solidity ^0.8.20;
      /**
       * @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;
          }
          function _contextSuffixLength() internal view virtual returns (uint256) {
              return 0;
          }
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v5.0.0) (utils/introspection/ERC165.sol)
      pragma solidity ^0.8.20;
      import {IERC165} from "./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);
       * }
       * ```
       */
      abstract contract ERC165 is IERC165 {
          /**
           * @dev See {IERC165-supportsInterface}.
           */
          function supportsInterface(bytes4 interfaceId) public view virtual returns (bool) {
              return interfaceId == type(IERC165).interfaceId;
          }
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v5.0.0) (utils/introspection/IERC165.sol)
      pragma solidity ^0.8.20;
      /**
       * @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 v5.0.0) (utils/math/Math.sol)
      pragma solidity ^0.8.20;
      /**
       * @dev Standard math utilities missing in the Solidity language.
       */
      library Math {
          /**
           * @dev Muldiv operation overflow.
           */
          error MathOverflowedMulDiv();
          enum Rounding {
              Floor, // Toward negative infinity
              Ceil, // Toward positive infinity
              Trunc, // Toward zero
              Expand // Away from zero
          }
          /**
           * @dev Returns the addition of two unsigned integers, with an overflow flag.
           */
          function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
              unchecked {
                  uint256 c = a + b;
                  if (c < a) return (false, 0);
                  return (true, c);
              }
          }
          /**
           * @dev Returns the subtraction of two unsigned integers, with an overflow flag.
           */
          function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
              unchecked {
                  if (b > a) return (false, 0);
                  return (true, a - b);
              }
          }
          /**
           * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
           */
          function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
              unchecked {
                  // 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-contracts/pull/522
                  if (a == 0) return (true, 0);
                  uint256 c = a * b;
                  if (c / a != b) return (false, 0);
                  return (true, c);
              }
          }
          /**
           * @dev Returns the division of two unsigned integers, with a division by zero flag.
           */
          function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
              unchecked {
                  if (b == 0) return (false, 0);
                  return (true, a / b);
              }
          }
          /**
           * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
           */
          function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
              unchecked {
                  if (b == 0) return (false, 0);
                  return (true, a % b);
              }
          }
          /**
           * @dev Returns the largest of two numbers.
           */
          function max(uint256 a, uint256 b) internal pure returns (uint256) {
              return a > b ? a : b;
          }
          /**
           * @dev Returns the smallest of two numbers.
           */
          function min(uint256 a, uint256 b) internal pure returns (uint256) {
              return a < b ? a : b;
          }
          /**
           * @dev Returns the average of two numbers. The result is rounded towards
           * zero.
           */
          function average(uint256 a, uint256 b) internal pure returns (uint256) {
              // (a + b) / 2 can overflow.
              return (a & b) + (a ^ b) / 2;
          }
          /**
           * @dev Returns the ceiling of the division of two numbers.
           *
           * This differs from standard division with `/` in that it rounds towards infinity instead
           * of rounding towards zero.
           */
          function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
              if (b == 0) {
                  // Guarantee the same behavior as in a regular Solidity division.
                  return a / b;
              }
              // (a + b - 1) / b can overflow on addition, so we distribute.
              return a == 0 ? 0 : (a - 1) / b + 1;
          }
          /**
           * @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or
           * denominator == 0.
           * @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv) with further edits by
           * Uniswap Labs also under MIT license.
           */
          function mulDiv(uint256 x, uint256 y, uint256 denominator) internal pure returns (uint256 result) {
              unchecked {
                  // 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
                  // use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
                  // variables such that product = prod1 * 2^256 + prod0.
                  uint256 prod0 = x * y; // Least significant 256 bits of the product
                  uint256 prod1; // Most significant 256 bits of the product
                  assembly {
                      let mm := mulmod(x, y, not(0))
                      prod1 := sub(sub(mm, prod0), lt(mm, prod0))
                  }
                  // Handle non-overflow cases, 256 by 256 division.
                  if (prod1 == 0) {
                      // Solidity will revert if denominator == 0, unlike the div opcode on its own.
                      // The surrounding unchecked block does not change this fact.
                      // See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
                      return prod0 / denominator;
                  }
                  // Make sure the result is less than 2^256. Also prevents denominator == 0.
                  if (denominator <= prod1) {
                      revert MathOverflowedMulDiv();
                  }
                  ///////////////////////////////////////////////
                  // 512 by 256 division.
                  ///////////////////////////////////////////////
                  // Make division exact by subtracting the remainder from [prod1 prod0].
                  uint256 remainder;
                  assembly {
                      // Compute remainder using mulmod.
                      remainder := mulmod(x, y, denominator)
                      // Subtract 256 bit number from 512 bit number.
                      prod1 := sub(prod1, gt(remainder, prod0))
                      prod0 := sub(prod0, remainder)
                  }
                  // Factor powers of two out of denominator and compute largest power of two divisor of denominator.
                  // Always >= 1. See https://cs.stackexchange.com/q/138556/92363.
                  uint256 twos = denominator & (0 - denominator);
                  assembly {
                      // Divide denominator by twos.
                      denominator := div(denominator, twos)
                      // Divide [prod1 prod0] by twos.
                      prod0 := div(prod0, twos)
                      // Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
                      twos := add(div(sub(0, twos), twos), 1)
                  }
                  // Shift in bits from prod1 into prod0.
                  prod0 |= prod1 * twos;
                  // Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
                  // that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
                  // four bits. That is, denominator * inv = 1 mod 2^4.
                  uint256 inverse = (3 * denominator) ^ 2;
                  // Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also
                  // works in modular arithmetic, doubling the correct bits in each step.
                  inverse *= 2 - denominator * inverse; // inverse mod 2^8
                  inverse *= 2 - denominator * inverse; // inverse mod 2^16
                  inverse *= 2 - denominator * inverse; // inverse mod 2^32
                  inverse *= 2 - denominator * inverse; // inverse mod 2^64
                  inverse *= 2 - denominator * inverse; // inverse mod 2^128
                  inverse *= 2 - denominator * inverse; // inverse mod 2^256
                  // Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
                  // This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
                  // less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
                  // is no longer required.
                  result = prod0 * inverse;
                  return result;
              }
          }
          /**
           * @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
           */
          function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
              uint256 result = mulDiv(x, y, denominator);
              if (unsignedRoundsUp(rounding) && mulmod(x, y, denominator) > 0) {
                  result += 1;
              }
              return result;
          }
          /**
           * @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded
           * towards zero.
           *
           * Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
           */
          function sqrt(uint256 a) internal pure returns (uint256) {
              if (a == 0) {
                  return 0;
              }
              // For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
              //
              // We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
              // `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
              //
              // This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
              // → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
              // → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
              //
              // Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
              uint256 result = 1 << (log2(a) >> 1);
              // At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
              // since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
              // every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
              // into the expected uint128 result.
              unchecked {
                  result = (result + a / result) >> 1;
                  result = (result + a / result) >> 1;
                  result = (result + a / result) >> 1;
                  result = (result + a / result) >> 1;
                  result = (result + a / result) >> 1;
                  result = (result + a / result) >> 1;
                  result = (result + a / result) >> 1;
                  return min(result, a / result);
              }
          }
          /**
           * @notice Calculates sqrt(a), following the selected rounding direction.
           */
          function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
              unchecked {
                  uint256 result = sqrt(a);
                  return result + (unsignedRoundsUp(rounding) && result * result < a ? 1 : 0);
              }
          }
          /**
           * @dev Return the log in base 2 of a positive value rounded towards zero.
           * Returns 0 if given 0.
           */
          function log2(uint256 value) internal pure returns (uint256) {
              uint256 result = 0;
              unchecked {
                  if (value >> 128 > 0) {
                      value >>= 128;
                      result += 128;
                  }
                  if (value >> 64 > 0) {
                      value >>= 64;
                      result += 64;
                  }
                  if (value >> 32 > 0) {
                      value >>= 32;
                      result += 32;
                  }
                  if (value >> 16 > 0) {
                      value >>= 16;
                      result += 16;
                  }
                  if (value >> 8 > 0) {
                      value >>= 8;
                      result += 8;
                  }
                  if (value >> 4 > 0) {
                      value >>= 4;
                      result += 4;
                  }
                  if (value >> 2 > 0) {
                      value >>= 2;
                      result += 2;
                  }
                  if (value >> 1 > 0) {
                      result += 1;
                  }
              }
              return result;
          }
          /**
           * @dev Return the log in base 2, following the selected rounding direction, of a positive value.
           * Returns 0 if given 0.
           */
          function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
              unchecked {
                  uint256 result = log2(value);
                  return result + (unsignedRoundsUp(rounding) && 1 << result < value ? 1 : 0);
              }
          }
          /**
           * @dev Return the log in base 10 of a positive value rounded towards zero.
           * Returns 0 if given 0.
           */
          function log10(uint256 value) internal pure returns (uint256) {
              uint256 result = 0;
              unchecked {
                  if (value >= 10 ** 64) {
                      value /= 10 ** 64;
                      result += 64;
                  }
                  if (value >= 10 ** 32) {
                      value /= 10 ** 32;
                      result += 32;
                  }
                  if (value >= 10 ** 16) {
                      value /= 10 ** 16;
                      result += 16;
                  }
                  if (value >= 10 ** 8) {
                      value /= 10 ** 8;
                      result += 8;
                  }
                  if (value >= 10 ** 4) {
                      value /= 10 ** 4;
                      result += 4;
                  }
                  if (value >= 10 ** 2) {
                      value /= 10 ** 2;
                      result += 2;
                  }
                  if (value >= 10 ** 1) {
                      result += 1;
                  }
              }
              return result;
          }
          /**
           * @dev Return the log in base 10, following the selected rounding direction, of a positive value.
           * Returns 0 if given 0.
           */
          function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
              unchecked {
                  uint256 result = log10(value);
                  return result + (unsignedRoundsUp(rounding) && 10 ** result < value ? 1 : 0);
              }
          }
          /**
           * @dev Return the log in base 256 of a positive value rounded towards zero.
           * Returns 0 if given 0.
           *
           * Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
           */
          function log256(uint256 value) internal pure returns (uint256) {
              uint256 result = 0;
              unchecked {
                  if (value >> 128 > 0) {
                      value >>= 128;
                      result += 16;
                  }
                  if (value >> 64 > 0) {
                      value >>= 64;
                      result += 8;
                  }
                  if (value >> 32 > 0) {
                      value >>= 32;
                      result += 4;
                  }
                  if (value >> 16 > 0) {
                      value >>= 16;
                      result += 2;
                  }
                  if (value >> 8 > 0) {
                      result += 1;
                  }
              }
              return result;
          }
          /**
           * @dev Return the log in base 256, following the selected rounding direction, of a positive value.
           * Returns 0 if given 0.
           */
          function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
              unchecked {
                  uint256 result = log256(value);
                  return result + (unsignedRoundsUp(rounding) && 1 << (result << 3) < value ? 1 : 0);
              }
          }
          /**
           * @dev Returns whether a provided rounding mode is considered rounding up for unsigned integers.
           */
          function unsignedRoundsUp(Rounding rounding) internal pure returns (bool) {
              return uint8(rounding) % 2 == 1;
          }
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v5.0.0) (utils/math/SafeCast.sol)
      // This file was procedurally generated from scripts/generate/templates/SafeCast.js.
      pragma solidity ^0.8.20;
      /**
       * @dev Wrappers over Solidity's uintXX/intXX casting operators with added overflow
       * checks.
       *
       * Downcasting from uint256/int256 in Solidity does not revert on overflow. This can
       * easily result in undesired exploitation or bugs, since developers usually
       * assume that overflows raise errors. `SafeCast` restores this intuition by
       * reverting the transaction when such an operation overflows.
       *
       * Using this library instead of the unchecked operations eliminates an entire
       * class of bugs, so it's recommended to use it always.
       */
      library SafeCast {
          /**
           * @dev Value doesn't fit in an uint of `bits` size.
           */
          error SafeCastOverflowedUintDowncast(uint8 bits, uint256 value);
          /**
           * @dev An int value doesn't fit in an uint of `bits` size.
           */
          error SafeCastOverflowedIntToUint(int256 value);
          /**
           * @dev Value doesn't fit in an int of `bits` size.
           */
          error SafeCastOverflowedIntDowncast(uint8 bits, int256 value);
          /**
           * @dev An uint value doesn't fit in an int of `bits` size.
           */
          error SafeCastOverflowedUintToInt(uint256 value);
          /**
           * @dev Returns the downcasted uint248 from uint256, reverting on
           * overflow (when the input is greater than largest uint248).
           *
           * Counterpart to Solidity's `uint248` operator.
           *
           * Requirements:
           *
           * - input must fit into 248 bits
           */
          function toUint248(uint256 value) internal pure returns (uint248) {
              if (value > type(uint248).max) {
                  revert SafeCastOverflowedUintDowncast(248, value);
              }
              return uint248(value);
          }
          /**
           * @dev Returns the downcasted uint240 from uint256, reverting on
           * overflow (when the input is greater than largest uint240).
           *
           * Counterpart to Solidity's `uint240` operator.
           *
           * Requirements:
           *
           * - input must fit into 240 bits
           */
          function toUint240(uint256 value) internal pure returns (uint240) {
              if (value > type(uint240).max) {
                  revert SafeCastOverflowedUintDowncast(240, value);
              }
              return uint240(value);
          }
          /**
           * @dev Returns the downcasted uint232 from uint256, reverting on
           * overflow (when the input is greater than largest uint232).
           *
           * Counterpart to Solidity's `uint232` operator.
           *
           * Requirements:
           *
           * - input must fit into 232 bits
           */
          function toUint232(uint256 value) internal pure returns (uint232) {
              if (value > type(uint232).max) {
                  revert SafeCastOverflowedUintDowncast(232, value);
              }
              return uint232(value);
          }
          /**
           * @dev Returns the downcasted uint224 from uint256, reverting on
           * overflow (when the input is greater than largest uint224).
           *
           * Counterpart to Solidity's `uint224` operator.
           *
           * Requirements:
           *
           * - input must fit into 224 bits
           */
          function toUint224(uint256 value) internal pure returns (uint224) {
              if (value > type(uint224).max) {
                  revert SafeCastOverflowedUintDowncast(224, value);
              }
              return uint224(value);
          }
          /**
           * @dev Returns the downcasted uint216 from uint256, reverting on
           * overflow (when the input is greater than largest uint216).
           *
           * Counterpart to Solidity's `uint216` operator.
           *
           * Requirements:
           *
           * - input must fit into 216 bits
           */
          function toUint216(uint256 value) internal pure returns (uint216) {
              if (value > type(uint216).max) {
                  revert SafeCastOverflowedUintDowncast(216, value);
              }
              return uint216(value);
          }
          /**
           * @dev Returns the downcasted uint208 from uint256, reverting on
           * overflow (when the input is greater than largest uint208).
           *
           * Counterpart to Solidity's `uint208` operator.
           *
           * Requirements:
           *
           * - input must fit into 208 bits
           */
          function toUint208(uint256 value) internal pure returns (uint208) {
              if (value > type(uint208).max) {
                  revert SafeCastOverflowedUintDowncast(208, value);
              }
              return uint208(value);
          }
          /**
           * @dev Returns the downcasted uint200 from uint256, reverting on
           * overflow (when the input is greater than largest uint200).
           *
           * Counterpart to Solidity's `uint200` operator.
           *
           * Requirements:
           *
           * - input must fit into 200 bits
           */
          function toUint200(uint256 value) internal pure returns (uint200) {
              if (value > type(uint200).max) {
                  revert SafeCastOverflowedUintDowncast(200, value);
              }
              return uint200(value);
          }
          /**
           * @dev Returns the downcasted uint192 from uint256, reverting on
           * overflow (when the input is greater than largest uint192).
           *
           * Counterpart to Solidity's `uint192` operator.
           *
           * Requirements:
           *
           * - input must fit into 192 bits
           */
          function toUint192(uint256 value) internal pure returns (uint192) {
              if (value > type(uint192).max) {
                  revert SafeCastOverflowedUintDowncast(192, value);
              }
              return uint192(value);
          }
          /**
           * @dev Returns the downcasted uint184 from uint256, reverting on
           * overflow (when the input is greater than largest uint184).
           *
           * Counterpart to Solidity's `uint184` operator.
           *
           * Requirements:
           *
           * - input must fit into 184 bits
           */
          function toUint184(uint256 value) internal pure returns (uint184) {
              if (value > type(uint184).max) {
                  revert SafeCastOverflowedUintDowncast(184, value);
              }
              return uint184(value);
          }
          /**
           * @dev Returns the downcasted uint176 from uint256, reverting on
           * overflow (when the input is greater than largest uint176).
           *
           * Counterpart to Solidity's `uint176` operator.
           *
           * Requirements:
           *
           * - input must fit into 176 bits
           */
          function toUint176(uint256 value) internal pure returns (uint176) {
              if (value > type(uint176).max) {
                  revert SafeCastOverflowedUintDowncast(176, value);
              }
              return uint176(value);
          }
          /**
           * @dev Returns the downcasted uint168 from uint256, reverting on
           * overflow (when the input is greater than largest uint168).
           *
           * Counterpart to Solidity's `uint168` operator.
           *
           * Requirements:
           *
           * - input must fit into 168 bits
           */
          function toUint168(uint256 value) internal pure returns (uint168) {
              if (value > type(uint168).max) {
                  revert SafeCastOverflowedUintDowncast(168, value);
              }
              return uint168(value);
          }
          /**
           * @dev Returns the downcasted uint160 from uint256, reverting on
           * overflow (when the input is greater than largest uint160).
           *
           * Counterpart to Solidity's `uint160` operator.
           *
           * Requirements:
           *
           * - input must fit into 160 bits
           */
          function toUint160(uint256 value) internal pure returns (uint160) {
              if (value > type(uint160).max) {
                  revert SafeCastOverflowedUintDowncast(160, value);
              }
              return uint160(value);
          }
          /**
           * @dev Returns the downcasted uint152 from uint256, reverting on
           * overflow (when the input is greater than largest uint152).
           *
           * Counterpart to Solidity's `uint152` operator.
           *
           * Requirements:
           *
           * - input must fit into 152 bits
           */
          function toUint152(uint256 value) internal pure returns (uint152) {
              if (value > type(uint152).max) {
                  revert SafeCastOverflowedUintDowncast(152, value);
              }
              return uint152(value);
          }
          /**
           * @dev Returns the downcasted uint144 from uint256, reverting on
           * overflow (when the input is greater than largest uint144).
           *
           * Counterpart to Solidity's `uint144` operator.
           *
           * Requirements:
           *
           * - input must fit into 144 bits
           */
          function toUint144(uint256 value) internal pure returns (uint144) {
              if (value > type(uint144).max) {
                  revert SafeCastOverflowedUintDowncast(144, value);
              }
              return uint144(value);
          }
          /**
           * @dev Returns the downcasted uint136 from uint256, reverting on
           * overflow (when the input is greater than largest uint136).
           *
           * Counterpart to Solidity's `uint136` operator.
           *
           * Requirements:
           *
           * - input must fit into 136 bits
           */
          function toUint136(uint256 value) internal pure returns (uint136) {
              if (value > type(uint136).max) {
                  revert SafeCastOverflowedUintDowncast(136, value);
              }
              return uint136(value);
          }
          /**
           * @dev Returns the downcasted uint128 from uint256, reverting on
           * overflow (when the input is greater than largest uint128).
           *
           * Counterpart to Solidity's `uint128` operator.
           *
           * Requirements:
           *
           * - input must fit into 128 bits
           */
          function toUint128(uint256 value) internal pure returns (uint128) {
              if (value > type(uint128).max) {
                  revert SafeCastOverflowedUintDowncast(128, value);
              }
              return uint128(value);
          }
          /**
           * @dev Returns the downcasted uint120 from uint256, reverting on
           * overflow (when the input is greater than largest uint120).
           *
           * Counterpart to Solidity's `uint120` operator.
           *
           * Requirements:
           *
           * - input must fit into 120 bits
           */
          function toUint120(uint256 value) internal pure returns (uint120) {
              if (value > type(uint120).max) {
                  revert SafeCastOverflowedUintDowncast(120, value);
              }
              return uint120(value);
          }
          /**
           * @dev Returns the downcasted uint112 from uint256, reverting on
           * overflow (when the input is greater than largest uint112).
           *
           * Counterpart to Solidity's `uint112` operator.
           *
           * Requirements:
           *
           * - input must fit into 112 bits
           */
          function toUint112(uint256 value) internal pure returns (uint112) {
              if (value > type(uint112).max) {
                  revert SafeCastOverflowedUintDowncast(112, value);
              }
              return uint112(value);
          }
          /**
           * @dev Returns the downcasted uint104 from uint256, reverting on
           * overflow (when the input is greater than largest uint104).
           *
           * Counterpart to Solidity's `uint104` operator.
           *
           * Requirements:
           *
           * - input must fit into 104 bits
           */
          function toUint104(uint256 value) internal pure returns (uint104) {
              if (value > type(uint104).max) {
                  revert SafeCastOverflowedUintDowncast(104, value);
              }
              return uint104(value);
          }
          /**
           * @dev Returns the downcasted uint96 from uint256, reverting on
           * overflow (when the input is greater than largest uint96).
           *
           * Counterpart to Solidity's `uint96` operator.
           *
           * Requirements:
           *
           * - input must fit into 96 bits
           */
          function toUint96(uint256 value) internal pure returns (uint96) {
              if (value > type(uint96).max) {
                  revert SafeCastOverflowedUintDowncast(96, value);
              }
              return uint96(value);
          }
          /**
           * @dev Returns the downcasted uint88 from uint256, reverting on
           * overflow (when the input is greater than largest uint88).
           *
           * Counterpart to Solidity's `uint88` operator.
           *
           * Requirements:
           *
           * - input must fit into 88 bits
           */
          function toUint88(uint256 value) internal pure returns (uint88) {
              if (value > type(uint88).max) {
                  revert SafeCastOverflowedUintDowncast(88, value);
              }
              return uint88(value);
          }
          /**
           * @dev Returns the downcasted uint80 from uint256, reverting on
           * overflow (when the input is greater than largest uint80).
           *
           * Counterpart to Solidity's `uint80` operator.
           *
           * Requirements:
           *
           * - input must fit into 80 bits
           */
          function toUint80(uint256 value) internal pure returns (uint80) {
              if (value > type(uint80).max) {
                  revert SafeCastOverflowedUintDowncast(80, value);
              }
              return uint80(value);
          }
          /**
           * @dev Returns the downcasted uint72 from uint256, reverting on
           * overflow (when the input is greater than largest uint72).
           *
           * Counterpart to Solidity's `uint72` operator.
           *
           * Requirements:
           *
           * - input must fit into 72 bits
           */
          function toUint72(uint256 value) internal pure returns (uint72) {
              if (value > type(uint72).max) {
                  revert SafeCastOverflowedUintDowncast(72, value);
              }
              return uint72(value);
          }
          /**
           * @dev Returns the downcasted uint64 from uint256, reverting on
           * overflow (when the input is greater than largest uint64).
           *
           * Counterpart to Solidity's `uint64` operator.
           *
           * Requirements:
           *
           * - input must fit into 64 bits
           */
          function toUint64(uint256 value) internal pure returns (uint64) {
              if (value > type(uint64).max) {
                  revert SafeCastOverflowedUintDowncast(64, value);
              }
              return uint64(value);
          }
          /**
           * @dev Returns the downcasted uint56 from uint256, reverting on
           * overflow (when the input is greater than largest uint56).
           *
           * Counterpart to Solidity's `uint56` operator.
           *
           * Requirements:
           *
           * - input must fit into 56 bits
           */
          function toUint56(uint256 value) internal pure returns (uint56) {
              if (value > type(uint56).max) {
                  revert SafeCastOverflowedUintDowncast(56, value);
              }
              return uint56(value);
          }
          /**
           * @dev Returns the downcasted uint48 from uint256, reverting on
           * overflow (when the input is greater than largest uint48).
           *
           * Counterpart to Solidity's `uint48` operator.
           *
           * Requirements:
           *
           * - input must fit into 48 bits
           */
          function toUint48(uint256 value) internal pure returns (uint48) {
              if (value > type(uint48).max) {
                  revert SafeCastOverflowedUintDowncast(48, value);
              }
              return uint48(value);
          }
          /**
           * @dev Returns the downcasted uint40 from uint256, reverting on
           * overflow (when the input is greater than largest uint40).
           *
           * Counterpart to Solidity's `uint40` operator.
           *
           * Requirements:
           *
           * - input must fit into 40 bits
           */
          function toUint40(uint256 value) internal pure returns (uint40) {
              if (value > type(uint40).max) {
                  revert SafeCastOverflowedUintDowncast(40, value);
              }
              return uint40(value);
          }
          /**
           * @dev Returns the downcasted uint32 from uint256, reverting on
           * overflow (when the input is greater than largest uint32).
           *
           * Counterpart to Solidity's `uint32` operator.
           *
           * Requirements:
           *
           * - input must fit into 32 bits
           */
          function toUint32(uint256 value) internal pure returns (uint32) {
              if (value > type(uint32).max) {
                  revert SafeCastOverflowedUintDowncast(32, value);
              }
              return uint32(value);
          }
          /**
           * @dev Returns the downcasted uint24 from uint256, reverting on
           * overflow (when the input is greater than largest uint24).
           *
           * Counterpart to Solidity's `uint24` operator.
           *
           * Requirements:
           *
           * - input must fit into 24 bits
           */
          function toUint24(uint256 value) internal pure returns (uint24) {
              if (value > type(uint24).max) {
                  revert SafeCastOverflowedUintDowncast(24, value);
              }
              return uint24(value);
          }
          /**
           * @dev Returns the downcasted uint16 from uint256, reverting on
           * overflow (when the input is greater than largest uint16).
           *
           * Counterpart to Solidity's `uint16` operator.
           *
           * Requirements:
           *
           * - input must fit into 16 bits
           */
          function toUint16(uint256 value) internal pure returns (uint16) {
              if (value > type(uint16).max) {
                  revert SafeCastOverflowedUintDowncast(16, value);
              }
              return uint16(value);
          }
          /**
           * @dev Returns the downcasted uint8 from uint256, reverting on
           * overflow (when the input is greater than largest uint8).
           *
           * Counterpart to Solidity's `uint8` operator.
           *
           * Requirements:
           *
           * - input must fit into 8 bits
           */
          function toUint8(uint256 value) internal pure returns (uint8) {
              if (value > type(uint8).max) {
                  revert SafeCastOverflowedUintDowncast(8, value);
              }
              return uint8(value);
          }
          /**
           * @dev Converts a signed int256 into an unsigned uint256.
           *
           * Requirements:
           *
           * - input must be greater than or equal to 0.
           */
          function toUint256(int256 value) internal pure returns (uint256) {
              if (value < 0) {
                  revert SafeCastOverflowedIntToUint(value);
              }
              return uint256(value);
          }
          /**
           * @dev Returns the downcasted int248 from int256, reverting on
           * overflow (when the input is less than smallest int248 or
           * greater than largest int248).
           *
           * Counterpart to Solidity's `int248` operator.
           *
           * Requirements:
           *
           * - input must fit into 248 bits
           */
          function toInt248(int256 value) internal pure returns (int248 downcasted) {
              downcasted = int248(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(248, value);
              }
          }
          /**
           * @dev Returns the downcasted int240 from int256, reverting on
           * overflow (when the input is less than smallest int240 or
           * greater than largest int240).
           *
           * Counterpart to Solidity's `int240` operator.
           *
           * Requirements:
           *
           * - input must fit into 240 bits
           */
          function toInt240(int256 value) internal pure returns (int240 downcasted) {
              downcasted = int240(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(240, value);
              }
          }
          /**
           * @dev Returns the downcasted int232 from int256, reverting on
           * overflow (when the input is less than smallest int232 or
           * greater than largest int232).
           *
           * Counterpart to Solidity's `int232` operator.
           *
           * Requirements:
           *
           * - input must fit into 232 bits
           */
          function toInt232(int256 value) internal pure returns (int232 downcasted) {
              downcasted = int232(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(232, value);
              }
          }
          /**
           * @dev Returns the downcasted int224 from int256, reverting on
           * overflow (when the input is less than smallest int224 or
           * greater than largest int224).
           *
           * Counterpart to Solidity's `int224` operator.
           *
           * Requirements:
           *
           * - input must fit into 224 bits
           */
          function toInt224(int256 value) internal pure returns (int224 downcasted) {
              downcasted = int224(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(224, value);
              }
          }
          /**
           * @dev Returns the downcasted int216 from int256, reverting on
           * overflow (when the input is less than smallest int216 or
           * greater than largest int216).
           *
           * Counterpart to Solidity's `int216` operator.
           *
           * Requirements:
           *
           * - input must fit into 216 bits
           */
          function toInt216(int256 value) internal pure returns (int216 downcasted) {
              downcasted = int216(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(216, value);
              }
          }
          /**
           * @dev Returns the downcasted int208 from int256, reverting on
           * overflow (when the input is less than smallest int208 or
           * greater than largest int208).
           *
           * Counterpart to Solidity's `int208` operator.
           *
           * Requirements:
           *
           * - input must fit into 208 bits
           */
          function toInt208(int256 value) internal pure returns (int208 downcasted) {
              downcasted = int208(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(208, value);
              }
          }
          /**
           * @dev Returns the downcasted int200 from int256, reverting on
           * overflow (when the input is less than smallest int200 or
           * greater than largest int200).
           *
           * Counterpart to Solidity's `int200` operator.
           *
           * Requirements:
           *
           * - input must fit into 200 bits
           */
          function toInt200(int256 value) internal pure returns (int200 downcasted) {
              downcasted = int200(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(200, value);
              }
          }
          /**
           * @dev Returns the downcasted int192 from int256, reverting on
           * overflow (when the input is less than smallest int192 or
           * greater than largest int192).
           *
           * Counterpart to Solidity's `int192` operator.
           *
           * Requirements:
           *
           * - input must fit into 192 bits
           */
          function toInt192(int256 value) internal pure returns (int192 downcasted) {
              downcasted = int192(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(192, value);
              }
          }
          /**
           * @dev Returns the downcasted int184 from int256, reverting on
           * overflow (when the input is less than smallest int184 or
           * greater than largest int184).
           *
           * Counterpart to Solidity's `int184` operator.
           *
           * Requirements:
           *
           * - input must fit into 184 bits
           */
          function toInt184(int256 value) internal pure returns (int184 downcasted) {
              downcasted = int184(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(184, value);
              }
          }
          /**
           * @dev Returns the downcasted int176 from int256, reverting on
           * overflow (when the input is less than smallest int176 or
           * greater than largest int176).
           *
           * Counterpart to Solidity's `int176` operator.
           *
           * Requirements:
           *
           * - input must fit into 176 bits
           */
          function toInt176(int256 value) internal pure returns (int176 downcasted) {
              downcasted = int176(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(176, value);
              }
          }
          /**
           * @dev Returns the downcasted int168 from int256, reverting on
           * overflow (when the input is less than smallest int168 or
           * greater than largest int168).
           *
           * Counterpart to Solidity's `int168` operator.
           *
           * Requirements:
           *
           * - input must fit into 168 bits
           */
          function toInt168(int256 value) internal pure returns (int168 downcasted) {
              downcasted = int168(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(168, value);
              }
          }
          /**
           * @dev Returns the downcasted int160 from int256, reverting on
           * overflow (when the input is less than smallest int160 or
           * greater than largest int160).
           *
           * Counterpart to Solidity's `int160` operator.
           *
           * Requirements:
           *
           * - input must fit into 160 bits
           */
          function toInt160(int256 value) internal pure returns (int160 downcasted) {
              downcasted = int160(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(160, value);
              }
          }
          /**
           * @dev Returns the downcasted int152 from int256, reverting on
           * overflow (when the input is less than smallest int152 or
           * greater than largest int152).
           *
           * Counterpart to Solidity's `int152` operator.
           *
           * Requirements:
           *
           * - input must fit into 152 bits
           */
          function toInt152(int256 value) internal pure returns (int152 downcasted) {
              downcasted = int152(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(152, value);
              }
          }
          /**
           * @dev Returns the downcasted int144 from int256, reverting on
           * overflow (when the input is less than smallest int144 or
           * greater than largest int144).
           *
           * Counterpart to Solidity's `int144` operator.
           *
           * Requirements:
           *
           * - input must fit into 144 bits
           */
          function toInt144(int256 value) internal pure returns (int144 downcasted) {
              downcasted = int144(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(144, value);
              }
          }
          /**
           * @dev Returns the downcasted int136 from int256, reverting on
           * overflow (when the input is less than smallest int136 or
           * greater than largest int136).
           *
           * Counterpart to Solidity's `int136` operator.
           *
           * Requirements:
           *
           * - input must fit into 136 bits
           */
          function toInt136(int256 value) internal pure returns (int136 downcasted) {
              downcasted = int136(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(136, value);
              }
          }
          /**
           * @dev Returns the downcasted int128 from int256, reverting on
           * overflow (when the input is less than smallest int128 or
           * greater than largest int128).
           *
           * Counterpart to Solidity's `int128` operator.
           *
           * Requirements:
           *
           * - input must fit into 128 bits
           */
          function toInt128(int256 value) internal pure returns (int128 downcasted) {
              downcasted = int128(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(128, value);
              }
          }
          /**
           * @dev Returns the downcasted int120 from int256, reverting on
           * overflow (when the input is less than smallest int120 or
           * greater than largest int120).
           *
           * Counterpart to Solidity's `int120` operator.
           *
           * Requirements:
           *
           * - input must fit into 120 bits
           */
          function toInt120(int256 value) internal pure returns (int120 downcasted) {
              downcasted = int120(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(120, value);
              }
          }
          /**
           * @dev Returns the downcasted int112 from int256, reverting on
           * overflow (when the input is less than smallest int112 or
           * greater than largest int112).
           *
           * Counterpart to Solidity's `int112` operator.
           *
           * Requirements:
           *
           * - input must fit into 112 bits
           */
          function toInt112(int256 value) internal pure returns (int112 downcasted) {
              downcasted = int112(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(112, value);
              }
          }
          /**
           * @dev Returns the downcasted int104 from int256, reverting on
           * overflow (when the input is less than smallest int104 or
           * greater than largest int104).
           *
           * Counterpart to Solidity's `int104` operator.
           *
           * Requirements:
           *
           * - input must fit into 104 bits
           */
          function toInt104(int256 value) internal pure returns (int104 downcasted) {
              downcasted = int104(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(104, value);
              }
          }
          /**
           * @dev Returns the downcasted int96 from int256, reverting on
           * overflow (when the input is less than smallest int96 or
           * greater than largest int96).
           *
           * Counterpart to Solidity's `int96` operator.
           *
           * Requirements:
           *
           * - input must fit into 96 bits
           */
          function toInt96(int256 value) internal pure returns (int96 downcasted) {
              downcasted = int96(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(96, value);
              }
          }
          /**
           * @dev Returns the downcasted int88 from int256, reverting on
           * overflow (when the input is less than smallest int88 or
           * greater than largest int88).
           *
           * Counterpart to Solidity's `int88` operator.
           *
           * Requirements:
           *
           * - input must fit into 88 bits
           */
          function toInt88(int256 value) internal pure returns (int88 downcasted) {
              downcasted = int88(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(88, value);
              }
          }
          /**
           * @dev Returns the downcasted int80 from int256, reverting on
           * overflow (when the input is less than smallest int80 or
           * greater than largest int80).
           *
           * Counterpart to Solidity's `int80` operator.
           *
           * Requirements:
           *
           * - input must fit into 80 bits
           */
          function toInt80(int256 value) internal pure returns (int80 downcasted) {
              downcasted = int80(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(80, value);
              }
          }
          /**
           * @dev Returns the downcasted int72 from int256, reverting on
           * overflow (when the input is less than smallest int72 or
           * greater than largest int72).
           *
           * Counterpart to Solidity's `int72` operator.
           *
           * Requirements:
           *
           * - input must fit into 72 bits
           */
          function toInt72(int256 value) internal pure returns (int72 downcasted) {
              downcasted = int72(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(72, value);
              }
          }
          /**
           * @dev Returns the downcasted int64 from int256, reverting on
           * overflow (when the input is less than smallest int64 or
           * greater than largest int64).
           *
           * Counterpart to Solidity's `int64` operator.
           *
           * Requirements:
           *
           * - input must fit into 64 bits
           */
          function toInt64(int256 value) internal pure returns (int64 downcasted) {
              downcasted = int64(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(64, value);
              }
          }
          /**
           * @dev Returns the downcasted int56 from int256, reverting on
           * overflow (when the input is less than smallest int56 or
           * greater than largest int56).
           *
           * Counterpart to Solidity's `int56` operator.
           *
           * Requirements:
           *
           * - input must fit into 56 bits
           */
          function toInt56(int256 value) internal pure returns (int56 downcasted) {
              downcasted = int56(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(56, value);
              }
          }
          /**
           * @dev Returns the downcasted int48 from int256, reverting on
           * overflow (when the input is less than smallest int48 or
           * greater than largest int48).
           *
           * Counterpart to Solidity's `int48` operator.
           *
           * Requirements:
           *
           * - input must fit into 48 bits
           */
          function toInt48(int256 value) internal pure returns (int48 downcasted) {
              downcasted = int48(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(48, value);
              }
          }
          /**
           * @dev Returns the downcasted int40 from int256, reverting on
           * overflow (when the input is less than smallest int40 or
           * greater than largest int40).
           *
           * Counterpart to Solidity's `int40` operator.
           *
           * Requirements:
           *
           * - input must fit into 40 bits
           */
          function toInt40(int256 value) internal pure returns (int40 downcasted) {
              downcasted = int40(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(40, value);
              }
          }
          /**
           * @dev Returns the downcasted int32 from int256, reverting on
           * overflow (when the input is less than smallest int32 or
           * greater than largest int32).
           *
           * Counterpart to Solidity's `int32` operator.
           *
           * Requirements:
           *
           * - input must fit into 32 bits
           */
          function toInt32(int256 value) internal pure returns (int32 downcasted) {
              downcasted = int32(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(32, value);
              }
          }
          /**
           * @dev Returns the downcasted int24 from int256, reverting on
           * overflow (when the input is less than smallest int24 or
           * greater than largest int24).
           *
           * Counterpart to Solidity's `int24` operator.
           *
           * Requirements:
           *
           * - input must fit into 24 bits
           */
          function toInt24(int256 value) internal pure returns (int24 downcasted) {
              downcasted = int24(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(24, value);
              }
          }
          /**
           * @dev Returns the downcasted int16 from int256, reverting on
           * overflow (when the input is less than smallest int16 or
           * greater than largest int16).
           *
           * Counterpart to Solidity's `int16` operator.
           *
           * Requirements:
           *
           * - input must fit into 16 bits
           */
          function toInt16(int256 value) internal pure returns (int16 downcasted) {
              downcasted = int16(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(16, value);
              }
          }
          /**
           * @dev Returns the downcasted int8 from int256, reverting on
           * overflow (when the input is less than smallest int8 or
           * greater than largest int8).
           *
           * Counterpart to Solidity's `int8` operator.
           *
           * Requirements:
           *
           * - input must fit into 8 bits
           */
          function toInt8(int256 value) internal pure returns (int8 downcasted) {
              downcasted = int8(value);
              if (downcasted != value) {
                  revert SafeCastOverflowedIntDowncast(8, value);
              }
          }
          /**
           * @dev Converts an unsigned uint256 into a signed int256.
           *
           * Requirements:
           *
           * - input must be less than or equal to maxInt256.
           */
          function toInt256(uint256 value) internal pure returns (int256) {
              // Note: Unsafe cast below is okay because `type(int256).max` is guaranteed to be positive
              if (value > uint256(type(int256).max)) {
                  revert SafeCastOverflowedUintToInt(value);
              }
              return int256(value);
          }
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v5.0.0) (utils/Pausable.sol)
      pragma solidity ^0.8.20;
      import {Context} from "../utils/Context.sol";
      /**
       * @dev Contract module which allows children to implement an emergency stop
       * mechanism that can be triggered by an authorized account.
       *
       * This module is used through inheritance. It will make available the
       * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
       * the functions of your contract. Note that they will not be pausable by
       * simply including this module, only once the modifiers are put in place.
       */
      abstract contract Pausable is Context {
          bool private _paused;
          /**
           * @dev Emitted when the pause is triggered by `account`.
           */
          event Paused(address account);
          /**
           * @dev Emitted when the pause is lifted by `account`.
           */
          event Unpaused(address account);
          /**
           * @dev The operation failed because the contract is paused.
           */
          error EnforcedPause();
          /**
           * @dev The operation failed because the contract is not paused.
           */
          error ExpectedPause();
          /**
           * @dev Initializes the contract in unpaused state.
           */
          constructor() {
              _paused = false;
          }
          /**
           * @dev Modifier to make a function callable only when the contract is not paused.
           *
           * Requirements:
           *
           * - The contract must not be paused.
           */
          modifier whenNotPaused() {
              _requireNotPaused();
              _;
          }
          /**
           * @dev Modifier to make a function callable only when the contract is paused.
           *
           * Requirements:
           *
           * - The contract must be paused.
           */
          modifier whenPaused() {
              _requirePaused();
              _;
          }
          /**
           * @dev Returns true if the contract is paused, and false otherwise.
           */
          function paused() public view virtual returns (bool) {
              return _paused;
          }
          /**
           * @dev Throws if the contract is paused.
           */
          function _requireNotPaused() internal view virtual {
              if (paused()) {
                  revert EnforcedPause();
              }
          }
          /**
           * @dev Throws if the contract is not paused.
           */
          function _requirePaused() internal view virtual {
              if (!paused()) {
                  revert ExpectedPause();
              }
          }
          /**
           * @dev Triggers stopped state.
           *
           * Requirements:
           *
           * - The contract must not be paused.
           */
          function _pause() internal virtual whenNotPaused {
              _paused = true;
              emit Paused(_msgSender());
          }
          /**
           * @dev Returns to normal state.
           *
           * Requirements:
           *
           * - The contract must be paused.
           */
          function _unpause() internal virtual whenPaused {
              _paused = false;
              emit Unpaused(_msgSender());
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.25;
      import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
      import {IERC20Permit} from "@openzeppelin/contracts/token/ERC20/extensions/IERC20Permit.sol";
      import {SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
      import {AccessControlDefaultAdminRules} from "@openzeppelin/contracts/access/extensions/AccessControlDefaultAdminRules.sol";
      import {Pausable} from "@openzeppelin/contracts/utils/Pausable.sol";
      import {ISimpleToken} from "contracts/interfaces/ISimpleToken.sol";
      import {IExternalRequestsManager} from "./interfaces/IExternalRequestsManager.sol";
      import {IAddressesWhitelist} from "./interfaces/IAddressesWhitelist.sol";
      contract ExternalRequestsManager is IExternalRequestsManager, AccessControlDefaultAdminRules, Pausable {
          using SafeERC20 for IERC20;
          bytes32 public constant SERVICE_ROLE = keccak256("SERVICE_ROLE");
          address public immutable ISSUE_TOKEN_ADDRESS;
          address public treasuryAddress;
          IAddressesWhitelist public providersWhitelist;
          bool public isWhitelistEnabled;
          mapping(address token => bool isAllowed) public allowedTokens;
          uint256 public burnRequestsCounter;
          mapping(uint256 id => Request request) public burnRequests;
          uint256 public mintRequestsCounter;
          mapping(uint256 id => Request request) public mintRequests;
          modifier onlyAllowedProviders() {
              if (isWhitelistEnabled && !providersWhitelist.isAllowedAccount(msg.sender)) {
                  revert UnknownProvider(msg.sender);
              }
              _;
          }
          modifier burnRequestExist(uint256 _id) {
              if (burnRequests[_id].provider == address(0)) {
                  revert BurnRequestNotExist(_id);
              }
              _;
          }
          modifier mintRequestExist(uint256 _id) {
              if (mintRequests[_id].provider == address(0)) {
                  revert MintRequestNotExist(_id);
              }
              _;
          }
          modifier allowedToken(address _tokenAddress) {
              _assertNonZero(_tokenAddress);
              if (!allowedTokens[_tokenAddress]) {
                  revert TokenNotAllowed(_tokenAddress);
              }
              _;
          }
          constructor(
              address _issueTokenAddress,
              address _treasuryAddress,
              address _providersWhitelistAddress,
              address[] memory _allowedTokenAddresses
          ) AccessControlDefaultAdminRules(1 days, msg.sender) {
              ISSUE_TOKEN_ADDRESS = _assertNonZero(_issueTokenAddress);
              treasuryAddress = _assertNonZero(_treasuryAddress);
              providersWhitelist = IAddressesWhitelist(_assertNonZero(_providersWhitelistAddress));
              for (uint256 i = 0; i < _allowedTokenAddresses.length; i++) {
                  address allowedTokenAddress = _allowedTokenAddresses[i];
                  _assertNonZero(allowedTokenAddress);
                  if (allowedTokenAddress.code.length == 0) revert InvalidTokenAddress(allowedTokenAddress);
                  allowedTokens[allowedTokenAddress] = true;
              }
              isWhitelistEnabled = true;
          }
          function setTreasury(address _treasuryAddress) external onlyRole(DEFAULT_ADMIN_ROLE) {
              _assertNonZero(_treasuryAddress);
              treasuryAddress = _treasuryAddress;
              emit TreasurySet(_treasuryAddress);
          }
          function setProvidersWhitelist(address _providersWhitelistAddress) external onlyRole(DEFAULT_ADMIN_ROLE) {
              _assertNonZero(_providersWhitelistAddress);
              if (_providersWhitelistAddress.code.length == 0) revert InvalidProvidersWhitelist(_providersWhitelistAddress);
              providersWhitelist = IAddressesWhitelist(_providersWhitelistAddress);
              emit ProvidersWhitelistSet(_providersWhitelistAddress);
          }
          function setWhitelistEnabled(bool _isEnabled) external onlyRole(DEFAULT_ADMIN_ROLE) {
              isWhitelistEnabled = _isEnabled;
              emit WhitelistEnabledSet(_isEnabled);
          }
          function addAllowedToken(address _allowedTokenAddress) external onlyRole(DEFAULT_ADMIN_ROLE) {
              _assertNonZero(_allowedTokenAddress);
              if (_allowedTokenAddress.code.length == 0) revert InvalidTokenAddress(_allowedTokenAddress);
              allowedTokens[_allowedTokenAddress] = true;
              emit AllowedTokenAdded(_allowedTokenAddress);
          }
          function removeAllowedToken(address _allowedTokenAddress) external onlyRole(DEFAULT_ADMIN_ROLE) {
              _assertNonZero(_allowedTokenAddress);
              allowedTokens[_allowedTokenAddress] = false;
              emit AllowedTokenRemoved(_allowedTokenAddress);
          }
          function pause() external onlyRole(DEFAULT_ADMIN_ROLE) {
              Pausable._pause();
          }
          function unpause() external onlyRole(DEFAULT_ADMIN_ROLE) {
              Pausable._unpause();
          }
          function requestMint(
              address _depositTokenAddress,
              uint256 _amount,
              uint256 _minMintAmount
          ) public onlyAllowedProviders allowedToken(_depositTokenAddress) whenNotPaused {
              _assertAmount(_amount);
              IERC20(_depositTokenAddress).safeTransferFrom(msg.sender, address(this), _amount);
              Request memory request = _addMintRequest(_depositTokenAddress, _amount, _minMintAmount);
              emit MintRequestCreated(
                  request.id,
                  request.provider,
                  request.token,
                  request.amount,
                  request.minExpectedAmount
              );
          }
          function requestMintWithPermit(
              address _depositTokenAddress,
              uint256 _amount,
              uint256 _minMintAmount,
              uint256 _deadline,
              uint8 _v,
              bytes32 _r,
              bytes32 _s
          ) external {
              IERC20Permit tokenPermit = IERC20Permit(_depositTokenAddress);
              // the use of `try/catch` allows the permit to fail and makes the code tolerant to frontrunning.
              // solhint-disable-next-line no-empty-blocks
              try tokenPermit.permit(msg.sender, address(this), _amount, _deadline, _v, _r, _s) {} catch {}
              requestMint(_depositTokenAddress, _amount, _minMintAmount);
          }
          function cancelMint(uint256 _id) external mintRequestExist(_id) {
              Request storage request = mintRequests[_id];
              _assertAddress(request.provider, msg.sender);
              _assertState(State.CREATED, request.state);
              request.state = State.CANCELLED;
              IERC20 depositedToken = IERC20(request.token);
              depositedToken.safeTransfer(request.provider, request.amount);
              emit MintRequestCancelled(_id);
          }
          function completeMint(
              bytes32 _idempotencyKey,
              uint256 _id,
              uint256 _mintAmount
          ) external onlyRole(SERVICE_ROLE) mintRequestExist(_id) {
              Request storage request = mintRequests[_id];
              _assertState(State.CREATED, request.state);
              if (_mintAmount < request.minExpectedAmount) revert InsufficientMintAmount(
                  _mintAmount,
                  request.minExpectedAmount
              );
              request.state = State.COMPLETED;
              IERC20 depositToken = IERC20(request.token);
              depositToken.safeTransfer(treasuryAddress, request.amount);
              ISimpleToken issueToken = ISimpleToken(ISSUE_TOKEN_ADDRESS);
              issueToken.mint(_idempotencyKey, request.provider, _mintAmount);
              emit MintRequestCompleted(_idempotencyKey, _id, _mintAmount);
          }
          function requestBurn(
              uint256 _issueTokenAmount,
              address _withdrawalTokenAddress,
              uint256 _minWithdrawalAmount
          ) public onlyAllowedProviders allowedToken(_withdrawalTokenAddress) whenNotPaused {
              _assertAmount(_issueTokenAmount);
              IERC20 issueToken = IERC20(ISSUE_TOKEN_ADDRESS);
              issueToken.safeTransferFrom(msg.sender, address(this), _issueTokenAmount);
              Request memory request = _addBurnRequest(
                  _withdrawalTokenAddress,
                  _issueTokenAmount,
                  _minWithdrawalAmount
              );
              emit BurnRequestCreated(
                  request.id,
                  request.provider,
                  request.token,
                  request.amount,
                  request.minExpectedAmount
              );
          }
          function requestBurnWithPermit(
              uint256 _issueTokenAmount,
              address _withdrawalTokenAddress,
              uint256 _minWithdrawalAmount,
              uint256 _deadline,
              uint8 _v,
              bytes32 _r,
              bytes32 _s
          ) external {
              IERC20Permit tokenPermit = IERC20Permit(ISSUE_TOKEN_ADDRESS);
              // the use of `try/catch` allows the permit to fail and makes the code tolerant to frontrunning.
              // solhint-disable-next-line no-empty-blocks
              try tokenPermit.permit(msg.sender, address(this), _issueTokenAmount, _deadline, _v, _r, _s) {} catch {}
              requestBurn(_issueTokenAmount, _withdrawalTokenAddress, _minWithdrawalAmount);
          }
          function cancelBurn(uint256 _id) external burnRequestExist(_id) {
              Request storage request = burnRequests[_id];
              _assertAddress(request.provider, msg.sender);
              _assertState(State.CREATED, request.state);
              request.state = State.CANCELLED;
              IERC20 issueToken = IERC20(ISSUE_TOKEN_ADDRESS);
              issueToken.safeTransfer(request.provider, request.amount);
              emit BurnRequestCancelled(_id);
          }
          function completeBurn(
              bytes32 _idempotencyKey,
              uint256 _id,
              uint256 _withdrawalAmount
          ) external onlyRole(SERVICE_ROLE) burnRequestExist(_id) {
              Request storage request = burnRequests[_id];
              _assertState(State.CREATED, request.state);
              if (_withdrawalAmount < request.minExpectedAmount) revert InsufficientWithdrawalAmount(
                  _withdrawalAmount,
                  request.minExpectedAmount
              );
              request.state = State.COMPLETED;
              ISimpleToken issueToken = ISimpleToken(ISSUE_TOKEN_ADDRESS);
              issueToken.burn(_idempotencyKey, address(this), request.amount);
              // slither-disable-next-line arbitrary-send-erc20
              IERC20(request.token).safeTransferFrom(treasuryAddress, request.provider, _withdrawalAmount);
              emit BurnRequestCompleted(_id, request.amount, _withdrawalAmount);
          }
          function emergencyWithdraw(IERC20 _token) external onlyRole(DEFAULT_ADMIN_ROLE) {
              uint256 balance = _token.balanceOf(address(this));
              _token.safeTransfer(msg.sender, balance);
              emit EmergencyWithdrawn(address(_token), balance);
          }
          function _addMintRequest(
              address _tokenAddress,
              uint256 _amount,
              uint256 _minExpectedAmount
          ) internal returns (Request memory mintRequest) {
              uint256 id = mintRequestsCounter;
              mintRequest = Request({
                  id: id,
                  provider: msg.sender,
                  state: State.CREATED,
                  amount: _amount,
                  token: _tokenAddress,
                  minExpectedAmount: _minExpectedAmount
              });
              mintRequests[id] = mintRequest;
              unchecked {mintRequestsCounter++;}
              return mintRequest;
          }
          function _addBurnRequest(
              address _tokenAddress,
              uint256 _amount,
              uint256 _minWithdrawalAmount
          ) internal returns (Request memory burnRequest) {
              uint256 id = burnRequestsCounter;
              burnRequest = Request({
                  id: id,
                  provider: msg.sender,
                  state: State.CREATED,
                  amount: _amount,
                  token: _tokenAddress,
                  minExpectedAmount: _minWithdrawalAmount
              });
              burnRequests[id] = burnRequest;
              unchecked {burnRequestsCounter++;}
              return burnRequest;
          }
          function _assertNonZero(address _address) internal pure returns (address nonZeroAddress) {
              if (_address == address(0)) revert ZeroAddress();
              return _address;
          }
          function _assertState(State _expected, State _current) internal pure {
              if (_expected != _current) revert IllegalState(_expected, _current);
          }
          function _assertAddress(address _expected, address _actual) internal pure {
              if (_expected != _actual) revert IllegalAddress(_expected, _actual);
          }
          function _assertAmount(uint256 _amount) internal pure {
              if (_amount == 0) revert InvalidAmount(_amount);
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.25;
      import {IDefaultErrors} from "./IDefaultErrors.sol";
      interface IAddressesWhitelist is IDefaultErrors {
          event AccountAdded(address _account);
          event AccountRemoved(address _account);
          function isAllowedAccount(address _account) external view returns (bool isAllowed);
      }
      // SPDX-License-Identifier: UNLICENSED
      pragma solidity ^0.8.25;
      interface IDefaultErrors {
          error IdempotencyKeyAlreadyExist(bytes32 _idempotencyKey);
          error InvalidAmount(uint256 _amount);
          error ZeroAddress();
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.25;
      import {IDefaultErrors} from "./IDefaultErrors.sol";
      import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
      interface IExternalRequestsManager is IDefaultErrors {
          event MintRequestCreated(
              uint256 indexed id,
              address indexed provider,
              address depositToken,
              uint256 amount,
              uint256 minMintAmount
          );
          event MintRequestCompleted(bytes32 indexed idempotencyKey, uint256 indexed id, uint256 mintedAmount);
          event MintRequestCancelled(uint256 indexed id);
          event BurnRequestCreated(
              uint256 indexed id,
              address indexed provider,
              address withdrawalTokenAddress,
              uint256 issueTokenAmount,
              uint256 minWithdrawalAmount
          );
          event BurnRequestCompleted(uint256 indexed id, uint256 burnedAmount, uint256 withdrawalAmount);
          event BurnRequestCancelled(uint256 indexed id);
          event TreasurySet(address treasuryAddress);
          event ProvidersWhitelistSet(address providersWhitelistAddress);
          event WhitelistEnabledSet(bool isEnabled);
          event AllowedTokenAdded(address tokenAddress);
          event AllowedTokenRemoved(address tokenAddres);
          event EmergencyWithdrawn(address tokenAddress, uint256 amount);
          error UnknownProvider(address account);
          error IllegalState(State expected, State current);
          error IllegalAddress(address expected, address actual);
          error MintRequestNotExist(uint256 id);
          error BurnRequestNotExist(uint256 id);
          error TokenNotAllowed(address token);
          error InvalidProvidersWhitelist(address providersWhitelistAddress);
          error InvalidTokenAddress(address token);
          error InsufficientMintAmount(uint256 mintAmount, uint256 minMintAmount);
          error InsufficientWithdrawalAmount(uint256 withdrawalAmount, uint256 minWithdrawalAmount);
          enum State {CREATED, COMPLETED, CANCELLED}
          struct Request {
              uint256 id;
              address provider;
              State state;
              uint256 amount;
              address token;
              uint256 minExpectedAmount;
          }
          function setTreasury(address _treasuryAddress) external;
          function setProvidersWhitelist(address _providersWhitelistAddress) external;
          function setWhitelistEnabled(bool _isEnabled) external;
          function addAllowedToken(address _allowedTokenAddress) external;
          function removeAllowedToken(address _allowedTokenAddress) external;
          function pause() external;
          function unpause() external;
          function requestMint(
              address _depositTokenAddress,
              uint256 _amount,
              uint256 _minMintAmount
          ) external;
          function requestMintWithPermit(
              address _depositTokenAddress,
              uint256 _amount,
              uint256 _minMintAmount,
              uint256 _deadline,
              uint8 _v,
              bytes32 _r,
              bytes32 _s
          ) external;
          function cancelMint(uint256 _id) external;
          function completeMint(bytes32 _idempotencyKey, uint256 _id, uint256 _mintAmount) external;
          function requestBurn(
              uint256 _issueTokenAmount,
              address _withdrawalTokenAddress,
              uint256 _minWithdrawalAmount
          ) external;
          function requestBurnWithPermit(
              uint256 _issueTokenAmount,
              address _withdrawalTokenAddress,
              uint256 _minWithdrawalAmount,
              uint256 _deadline,
              uint8 _v,
              bytes32 _r,
              bytes32 _s
          ) external;
          function cancelBurn(uint256 _id) external;
          function completeBurn(bytes32 _idempotencyKey, uint256 _id, uint256 _withdrawalAmount) external;
          function emergencyWithdraw(IERC20 _token) external;
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.25;
      interface ISimpleToken {
          error IdempotencyKeyAlreadyExist(bytes32 idempotencyKey);
          function mint(address _account, uint256 _amount) external;
          function mint(bytes32 _idempotencyKey, address _account, uint256 _amount) external;
          function burn(address _account, uint256 _amount) external;
          function burn(bytes32 _idempotencyKey, address _account, uint256 _amount) external;
      }
      

      File 2 of 4: FiatTokenProxy
      pragma solidity ^0.4.24;
      
      // File: zos-lib/contracts/upgradeability/Proxy.sol
      
      /**
       * @title Proxy
       * @dev Implements delegation of calls to other contracts, with proper
       * forwarding of return values and bubbling of failures.
       * It defines a fallback function that delegates all calls to the address
       * returned by the abstract _implementation() internal function.
       */
      contract Proxy {
        /**
         * @dev Fallback function.
         * Implemented entirely in `_fallback`.
         */
        function () payable external {
          _fallback();
        }
      
        /**
         * @return The Address of the implementation.
         */
        function _implementation() internal view returns (address);
      
        /**
         * @dev Delegates execution to an implementation contract.
         * This is a low level function that doesn't return to its internal call site.
         * It will return to the external caller whatever the implementation returns.
         * @param implementation Address to delegate.
         */
        function _delegate(address implementation) internal {
          assembly {
            // Copy msg.data. We take full control of memory in this inline assembly
            // block because it will not return to Solidity code. We overwrite the
            // Solidity scratch pad at memory position 0.
            calldatacopy(0, 0, calldatasize)
      
            // Call the implementation.
            // out and outsize are 0 because we don't know the size yet.
            let result := delegatecall(gas, implementation, 0, calldatasize, 0, 0)
      
            // Copy the returned data.
            returndatacopy(0, 0, returndatasize)
      
            switch result
            // delegatecall returns 0 on error.
            case 0 { revert(0, returndatasize) }
            default { return(0, returndatasize) }
          }
        }
      
        /**
         * @dev Function that is run as the first thing in the fallback function.
         * Can be redefined in derived contracts to add functionality.
         * Redefinitions must call super._willFallback().
         */
        function _willFallback() internal {
        }
      
        /**
         * @dev fallback implementation.
         * Extracted to enable manual triggering.
         */
        function _fallback() internal {
          _willFallback();
          _delegate(_implementation());
        }
      }
      
      // File: openzeppelin-solidity/contracts/AddressUtils.sol
      
      /**
       * Utility library of inline functions on addresses
       */
      library AddressUtils {
      
        /**
         * Returns whether the target address is a contract
         * @dev This function will return false if invoked during the constructor of a contract,
         * as the code is not actually created until after the constructor finishes.
         * @param addr address to check
         * @return whether the target address is a contract
         */
        function isContract(address addr) internal view returns (bool) {
          uint256 size;
          // XXX Currently there is no better way to check if there is a contract in an address
          // than to check the size of the code at that address.
          // See https://ethereum.stackexchange.com/a/14016/36603
          // for more details about how this works.
          // TODO Check this again before the Serenity release, because all addresses will be
          // contracts then.
          // solium-disable-next-line security/no-inline-assembly
          assembly { size := extcodesize(addr) }
          return size > 0;
        }
      
      }
      
      // File: zos-lib/contracts/upgradeability/UpgradeabilityProxy.sol
      
      /**
       * @title UpgradeabilityProxy
       * @dev This contract implements a proxy that allows to change the
       * implementation address to which it will delegate.
       * Such a change is called an implementation upgrade.
       */
      contract UpgradeabilityProxy is Proxy {
        /**
         * @dev Emitted when the implementation is upgraded.
         * @param implementation Address of the new implementation.
         */
        event Upgraded(address implementation);
      
        /**
         * @dev Storage slot with the address of the current implementation.
         * This is the keccak-256 hash of "org.zeppelinos.proxy.implementation", and is
         * validated in the constructor.
         */
        bytes32 private constant IMPLEMENTATION_SLOT = 0x7050c9e0f4ca769c69bd3a8ef740bc37934f8e2c036e5a723fd8ee048ed3f8c3;
      
        /**
         * @dev Contract constructor.
         * @param _implementation Address of the initial implementation.
         */
        constructor(address _implementation) public {
          assert(IMPLEMENTATION_SLOT == keccak256("org.zeppelinos.proxy.implementation"));
      
          _setImplementation(_implementation);
        }
      
        /**
         * @dev Returns the current implementation.
         * @return Address of the current implementation
         */
        function _implementation() internal view returns (address impl) {
          bytes32 slot = IMPLEMENTATION_SLOT;
          assembly {
            impl := sload(slot)
          }
        }
      
        /**
         * @dev Upgrades the proxy to a new implementation.
         * @param newImplementation Address of the new implementation.
         */
        function _upgradeTo(address newImplementation) internal {
          _setImplementation(newImplementation);
          emit Upgraded(newImplementation);
        }
      
        /**
         * @dev Sets the implementation address of the proxy.
         * @param newImplementation Address of the new implementation.
         */
        function _setImplementation(address newImplementation) private {
          require(AddressUtils.isContract(newImplementation), "Cannot set a proxy implementation to a non-contract address");
      
          bytes32 slot = IMPLEMENTATION_SLOT;
      
          assembly {
            sstore(slot, newImplementation)
          }
        }
      }
      
      // File: zos-lib/contracts/upgradeability/AdminUpgradeabilityProxy.sol
      
      /**
       * @title AdminUpgradeabilityProxy
       * @dev This contract combines an upgradeability proxy with an authorization
       * mechanism for administrative tasks.
       * All external functions in this contract must be guarded by the
       * `ifAdmin` modifier. See ethereum/solidity#3864 for a Solidity
       * feature proposal that would enable this to be done automatically.
       */
      contract AdminUpgradeabilityProxy is UpgradeabilityProxy {
        /**
         * @dev Emitted when the administration has been transferred.
         * @param previousAdmin Address of the previous admin.
         * @param newAdmin Address of the new admin.
         */
        event AdminChanged(address previousAdmin, address newAdmin);
      
        /**
         * @dev Storage slot with the admin of the contract.
         * This is the keccak-256 hash of "org.zeppelinos.proxy.admin", and is
         * validated in the constructor.
         */
        bytes32 private constant ADMIN_SLOT = 0x10d6a54a4754c8869d6886b5f5d7fbfa5b4522237ea5c60d11bc4e7a1ff9390b;
      
        /**
         * @dev Modifier to check whether the `msg.sender` is the admin.
         * If it is, it will run the function. Otherwise, it will delegate the call
         * to the implementation.
         */
        modifier ifAdmin() {
          if (msg.sender == _admin()) {
            _;
          } else {
            _fallback();
          }
        }
      
        /**
         * Contract constructor.
         * It sets the `msg.sender` as the proxy administrator.
         * @param _implementation address of the initial implementation.
         */
        constructor(address _implementation) UpgradeabilityProxy(_implementation) public {
          assert(ADMIN_SLOT == keccak256("org.zeppelinos.proxy.admin"));
      
          _setAdmin(msg.sender);
        }
      
        /**
         * @return The address of the proxy admin.
         */
        function admin() external view ifAdmin returns (address) {
          return _admin();
        }
      
        /**
         * @return The address of the implementation.
         */
        function implementation() external view ifAdmin returns (address) {
          return _implementation();
        }
      
        /**
         * @dev Changes the admin of the proxy.
         * Only the current admin can call this function.
         * @param newAdmin Address to transfer proxy administration to.
         */
        function changeAdmin(address newAdmin) external ifAdmin {
          require(newAdmin != address(0), "Cannot change the admin of a proxy to the zero address");
          emit AdminChanged(_admin(), newAdmin);
          _setAdmin(newAdmin);
        }
      
        /**
         * @dev Upgrade the backing implementation of the proxy.
         * Only the admin can call this function.
         * @param newImplementation Address of the new implementation.
         */
        function upgradeTo(address newImplementation) external ifAdmin {
          _upgradeTo(newImplementation);
        }
      
        /**
         * @dev Upgrade the backing implementation of the proxy and call a function
         * on the new implementation.
         * This is useful to initialize the proxied contract.
         * @param newImplementation Address of the new implementation.
         * @param data Data to send as msg.data in the low level call.
         * It should include the signature and the parameters of the function to be
         * called, as described in
         * https://solidity.readthedocs.io/en/develop/abi-spec.html#function-selector-and-argument-encoding.
         */
        function upgradeToAndCall(address newImplementation, bytes data) payable external ifAdmin {
          _upgradeTo(newImplementation);
          require(address(this).call.value(msg.value)(data));
        }
      
        /**
         * @return The admin slot.
         */
        function _admin() internal view returns (address adm) {
          bytes32 slot = ADMIN_SLOT;
          assembly {
            adm := sload(slot)
          }
        }
      
        /**
         * @dev Sets the address of the proxy admin.
         * @param newAdmin Address of the new proxy admin.
         */
        function _setAdmin(address newAdmin) internal {
          bytes32 slot = ADMIN_SLOT;
      
          assembly {
            sstore(slot, newAdmin)
          }
        }
      
        /**
         * @dev Only fall back when the sender is not the admin.
         */
        function _willFallback() internal {
          require(msg.sender != _admin(), "Cannot call fallback function from the proxy admin");
          super._willFallback();
        }
      }
      
      // File: contracts/FiatTokenProxy.sol
      
      /**
      * Copyright CENTRE SECZ 2018
      *
      * Permission is hereby granted, free of charge, to any person obtaining a copy 
      * of this software and associated documentation files (the "Software"), to deal 
      * in the Software without restriction, including without limitation the rights 
      * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 
      * copies of the Software, and to permit persons to whom the Software is furnished to 
      * do so, subject to the following conditions:
      *
      * The above copyright notice and this permission notice shall be included in all 
      * copies or substantial portions of the Software.
      *
      * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
      * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
      * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
      * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
      * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 
      * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
      */
      
      pragma solidity ^0.4.24;
      
      
      /**
       * @title FiatTokenProxy
       * @dev This contract proxies FiatToken calls and enables FiatToken upgrades
      */ 
      contract FiatTokenProxy is AdminUpgradeabilityProxy {
          constructor(address _implementation) public AdminUpgradeabilityProxy(_implementation) {
          }
      }

      File 3 of 4: AddressesWhitelist
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v5.0.0) (access/Ownable.sol)
      pragma solidity ^0.8.20;
      import {Context} from "../utils/Context.sol";
      /**
       * @dev Contract module which provides a basic access control mechanism, where
       * there is an account (an owner) that can be granted exclusive access to
       * specific functions.
       *
       * The initial owner is set to the address provided by the deployer. This can
       * later be changed with {transferOwnership}.
       *
       * This module is used through inheritance. It will make available the modifier
       * `onlyOwner`, which can be applied to your functions to restrict their use to
       * the owner.
       */
      abstract contract Ownable is Context {
          address private _owner;
          /**
           * @dev The caller account is not authorized to perform an operation.
           */
          error OwnableUnauthorizedAccount(address account);
          /**
           * @dev The owner is not a valid owner account. (eg. `address(0)`)
           */
          error OwnableInvalidOwner(address owner);
          event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
          /**
           * @dev Initializes the contract setting the address provided by the deployer as the initial owner.
           */
          constructor(address initialOwner) {
              if (initialOwner == address(0)) {
                  revert OwnableInvalidOwner(address(0));
              }
              _transferOwnership(initialOwner);
          }
          /**
           * @dev Throws if called by any account other than the owner.
           */
          modifier onlyOwner() {
              _checkOwner();
              _;
          }
          /**
           * @dev Returns the address of the current owner.
           */
          function owner() public view virtual returns (address) {
              return _owner;
          }
          /**
           * @dev Throws if the sender is not the owner.
           */
          function _checkOwner() internal view virtual {
              if (owner() != _msgSender()) {
                  revert OwnableUnauthorizedAccount(_msgSender());
              }
          }
          /**
           * @dev Leaves the contract without owner. It will not be possible to call
           * `onlyOwner` functions. Can only be called by the current owner.
           *
           * NOTE: Renouncing ownership will leave the contract without an owner,
           * thereby disabling any functionality that is only available to the owner.
           */
          function renounceOwnership() public virtual onlyOwner {
              _transferOwnership(address(0));
          }
          /**
           * @dev Transfers ownership of the contract to a new account (`newOwner`).
           * Can only be called by the current owner.
           */
          function transferOwnership(address newOwner) public virtual onlyOwner {
              if (newOwner == address(0)) {
                  revert OwnableInvalidOwner(address(0));
              }
              _transferOwnership(newOwner);
          }
          /**
           * @dev Transfers ownership of the contract to a new account (`newOwner`).
           * Internal function without access restriction.
           */
          function _transferOwnership(address newOwner) internal virtual {
              address oldOwner = _owner;
              _owner = newOwner;
              emit OwnershipTransferred(oldOwner, newOwner);
          }
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v5.0.0) (access/Ownable2Step.sol)
      pragma solidity ^0.8.20;
      import {Ownable} from "./Ownable.sol";
      /**
       * @dev Contract module which provides access control mechanism, where
       * there is an account (an owner) that can be granted exclusive access to
       * specific functions.
       *
       * The initial owner is specified at deployment time in the constructor for `Ownable`. This
       * can later be changed with {transferOwnership} and {acceptOwnership}.
       *
       * This module is used through inheritance. It will make available all functions
       * from parent (Ownable).
       */
      abstract contract Ownable2Step is Ownable {
          address private _pendingOwner;
          event OwnershipTransferStarted(address indexed previousOwner, address indexed newOwner);
          /**
           * @dev Returns the address of the pending owner.
           */
          function pendingOwner() public view virtual returns (address) {
              return _pendingOwner;
          }
          /**
           * @dev Starts the ownership transfer of the contract to a new account. Replaces the pending transfer if there is one.
           * Can only be called by the current owner.
           */
          function transferOwnership(address newOwner) public virtual override onlyOwner {
              _pendingOwner = newOwner;
              emit OwnershipTransferStarted(owner(), newOwner);
          }
          /**
           * @dev Transfers ownership of the contract to a new account (`newOwner`) and deletes any pending owner.
           * Internal function without access restriction.
           */
          function _transferOwnership(address newOwner) internal virtual override {
              delete _pendingOwner;
              super._transferOwnership(newOwner);
          }
          /**
           * @dev The new owner accepts the ownership transfer.
           */
          function acceptOwnership() public virtual {
              address sender = _msgSender();
              if (pendingOwner() != sender) {
                  revert OwnableUnauthorizedAccount(sender);
              }
              _transferOwnership(sender);
          }
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v5.0.1) (utils/Context.sol)
      pragma solidity ^0.8.20;
      /**
       * @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;
          }
          function _contextSuffixLength() internal view virtual returns (uint256) {
              return 0;
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.25;
      import {Ownable2Step, Ownable} from "@openzeppelin/contracts/access/Ownable2Step.sol";
      import {IAddressesWhitelist} from "./interfaces/IAddressesWhitelist.sol";
      contract AddressesWhitelist is IAddressesWhitelist, Ownable2Step {
          mapping(address account => bool isAllowed) private allowedAccounts;
          constructor() Ownable(msg.sender) {}
          function addAccount(address _account) external onlyOwner {
              if (_account == address(0)) revert ZeroAddress();
              allowedAccounts[_account] = true;
              emit AccountAdded(_account);
          }
          function removeAccount(address _account) external onlyOwner {
              if (_account == address(0)) revert ZeroAddress();
              allowedAccounts[_account] = false;
              emit AccountRemoved(_account);
          }
          function isAllowedAccount(address _account) external view returns (bool isAllowed) {
              return allowedAccounts[_account];
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.25;
      import {IDefaultErrors} from "./IDefaultErrors.sol";
      interface IAddressesWhitelist is IDefaultErrors {
          event AccountAdded(address _account);
          event AccountRemoved(address _account);
          function isAllowedAccount(address _account) external view returns (bool isAllowed);
      }
      // SPDX-License-Identifier: UNLICENSED
      pragma solidity ^0.8.25;
      interface IDefaultErrors {
          error IdempotencyKeyAlreadyExist(bytes32 _idempotencyKey);
          error InvalidAmount(uint256 _amount);
          error ZeroAddress();
      }
      

      File 4 of 4: FiatTokenV2_2
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * Licensed under the Apache License, Version 2.0 (the "License");
       * you may not use this file except in compliance with the License.
       * You may obtain a copy of the License at
       *
       * http://www.apache.org/licenses/LICENSE-2.0
       *
       * Unless required by applicable law or agreed to in writing, software
       * distributed under the License is distributed on an "AS IS" BASIS,
       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
       * See the License for the specific language governing permissions and
       * limitations under the License.
       */
      pragma solidity 0.6.12;
      import { EIP712Domain } from "./EIP712Domain.sol"; // solhint-disable-line no-unused-import
      import { Blacklistable } from "../v1/Blacklistable.sol"; // solhint-disable-line no-unused-import
      import { FiatTokenV1 } from "../v1/FiatTokenV1.sol"; // solhint-disable-line no-unused-import
      import { FiatTokenV2 } from "./FiatTokenV2.sol"; // solhint-disable-line no-unused-import
      import { FiatTokenV2_1 } from "./FiatTokenV2_1.sol";
      import { EIP712 } from "../util/EIP712.sol";
      // solhint-disable func-name-mixedcase
      /**
       * @title FiatToken V2.2
       * @notice ERC20 Token backed by fiat reserves, version 2.2
       */
      contract FiatTokenV2_2 is FiatTokenV2_1 {
          /**
           * @notice Initialize v2.2
           * @param accountsToBlacklist   A list of accounts to migrate from the old blacklist
           * @param newSymbol             New token symbol
           * data structure to the new blacklist data structure.
           */
          function initializeV2_2(
              address[] calldata accountsToBlacklist,
              string calldata newSymbol
          ) external {
              // solhint-disable-next-line reason-string
              require(_initializedVersion == 2);
              // Update fiat token symbol
              symbol = newSymbol;
              // Add previously blacklisted accounts to the new blacklist data structure
              // and remove them from the old blacklist data structure.
              for (uint256 i = 0; i < accountsToBlacklist.length; i++) {
                  require(
                      _deprecatedBlacklisted[accountsToBlacklist[i]],
                      "FiatTokenV2_2: Blacklisting previously unblacklisted account!"
                  );
                  _blacklist(accountsToBlacklist[i]);
                  delete _deprecatedBlacklisted[accountsToBlacklist[i]];
              }
              _blacklist(address(this));
              delete _deprecatedBlacklisted[address(this)];
              _initializedVersion = 3;
          }
          /**
           * @dev Internal function to get the current chain id.
           * @return The current chain id.
           */
          function _chainId() internal virtual view returns (uint256) {
              uint256 chainId;
              assembly {
                  chainId := chainid()
              }
              return chainId;
          }
          /**
           * @inheritdoc EIP712Domain
           */
          function _domainSeparator() internal override view returns (bytes32) {
              return EIP712.makeDomainSeparator(name, "2", _chainId());
          }
          /**
           * @notice Update allowance with a signed permit
           * @dev EOA wallet signatures should be packed in the order of r, s, v.
           * @param owner       Token owner's address (Authorizer)
           * @param spender     Spender's address
           * @param value       Amount of allowance
           * @param deadline    The time at which the signature expires (unix time), or max uint256 value to signal no expiration
           * @param signature   Signature bytes signed by an EOA wallet or a contract wallet
           */
          function permit(
              address owner,
              address spender,
              uint256 value,
              uint256 deadline,
              bytes memory signature
          ) external whenNotPaused {
              _permit(owner, spender, value, deadline, signature);
          }
          /**
           * @notice Execute a transfer with a signed authorization
           * @dev EOA wallet signatures should be packed in the order of r, s, v.
           * @param from          Payer's address (Authorizer)
           * @param to            Payee's address
           * @param value         Amount to be transferred
           * @param validAfter    The time after which this is valid (unix time)
           * @param validBefore   The time before which this is valid (unix time)
           * @param nonce         Unique nonce
           * @param signature     Signature bytes signed by an EOA wallet or a contract wallet
           */
          function transferWithAuthorization(
              address from,
              address to,
              uint256 value,
              uint256 validAfter,
              uint256 validBefore,
              bytes32 nonce,
              bytes memory signature
          ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
              _transferWithAuthorization(
                  from,
                  to,
                  value,
                  validAfter,
                  validBefore,
                  nonce,
                  signature
              );
          }
          /**
           * @notice Receive a transfer with a signed authorization from the payer
           * @dev This has an additional check to ensure that the payee's address
           * matches the caller of this function to prevent front-running attacks.
           * EOA wallet signatures should be packed in the order of r, s, v.
           * @param from          Payer's address (Authorizer)
           * @param to            Payee's address
           * @param value         Amount to be transferred
           * @param validAfter    The time after which this is valid (unix time)
           * @param validBefore   The time before which this is valid (unix time)
           * @param nonce         Unique nonce
           * @param signature     Signature bytes signed by an EOA wallet or a contract wallet
           */
          function receiveWithAuthorization(
              address from,
              address to,
              uint256 value,
              uint256 validAfter,
              uint256 validBefore,
              bytes32 nonce,
              bytes memory signature
          ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
              _receiveWithAuthorization(
                  from,
                  to,
                  value,
                  validAfter,
                  validBefore,
                  nonce,
                  signature
              );
          }
          /**
           * @notice Attempt to cancel an authorization
           * @dev Works only if the authorization is not yet used.
           * EOA wallet signatures should be packed in the order of r, s, v.
           * @param authorizer    Authorizer's address
           * @param nonce         Nonce of the authorization
           * @param signature     Signature bytes signed by an EOA wallet or a contract wallet
           */
          function cancelAuthorization(
              address authorizer,
              bytes32 nonce,
              bytes memory signature
          ) external whenNotPaused {
              _cancelAuthorization(authorizer, nonce, signature);
          }
          /**
           * @dev Helper method that sets the blacklist state of an account on balanceAndBlacklistStates.
           * If _shouldBlacklist is true, we apply a (1 << 255) bitmask with an OR operation on the
           * account's balanceAndBlacklistState. This flips the high bit for the account to 1,
           * indicating that the account is blacklisted.
           *
           * If _shouldBlacklist if false, we reset the account's balanceAndBlacklistStates to their
           * balances. This clears the high bit for the account, indicating that the account is unblacklisted.
           * @param _account         The address of the account.
           * @param _shouldBlacklist True if the account should be blacklisted, false if the account should be unblacklisted.
           */
          function _setBlacklistState(address _account, bool _shouldBlacklist)
              internal
              override
          {
              balanceAndBlacklistStates[_account] = _shouldBlacklist
                  ? balanceAndBlacklistStates[_account] | (1 << 255)
                  : _balanceOf(_account);
          }
          /**
           * @dev Helper method that sets the balance of an account on balanceAndBlacklistStates.
           * Since balances are stored in the last 255 bits of the balanceAndBlacklistStates value,
           * we need to ensure that the updated balance does not exceed (2^255 - 1).
           * Since blacklisted accounts' balances cannot be updated, the method will also
           * revert if the account is blacklisted
           * @param _account The address of the account.
           * @param _balance The new fiat token balance of the account (max: (2^255 - 1)).
           */
          function _setBalance(address _account, uint256 _balance) internal override {
              require(
                  _balance <= ((1 << 255) - 1),
                  "FiatTokenV2_2: Balance exceeds (2^255 - 1)"
              );
              require(
                  !_isBlacklisted(_account),
                  "FiatTokenV2_2: Account is blacklisted"
              );
              balanceAndBlacklistStates[_account] = _balance;
          }
          /**
           * @inheritdoc Blacklistable
           */
          function _isBlacklisted(address _account)
              internal
              override
              view
              returns (bool)
          {
              return balanceAndBlacklistStates[_account] >> 255 == 1;
          }
          /**
           * @dev Helper method to obtain the balance of an account. Since balances
           * are stored in the last 255 bits of the balanceAndBlacklistStates value,
           * we apply a ((1 << 255) - 1) bit bitmask with an AND operation on the
           * balanceAndBlacklistState to obtain the balance.
           * @param _account  The address of the account.
           * @return          The fiat token balance of the account.
           */
          function _balanceOf(address _account)
              internal
              override
              view
              returns (uint256)
          {
              return balanceAndBlacklistStates[_account] & ((1 << 255) - 1);
          }
          /**
           * @inheritdoc FiatTokenV1
           */
          function approve(address spender, uint256 value)
              external
              override
              whenNotPaused
              returns (bool)
          {
              _approve(msg.sender, spender, value);
              return true;
          }
          /**
           * @inheritdoc FiatTokenV2
           */
          function permit(
              address owner,
              address spender,
              uint256 value,
              uint256 deadline,
              uint8 v,
              bytes32 r,
              bytes32 s
          ) external override whenNotPaused {
              _permit(owner, spender, value, deadline, v, r, s);
          }
          /**
           * @inheritdoc FiatTokenV2
           */
          function increaseAllowance(address spender, uint256 increment)
              external
              override
              whenNotPaused
              returns (bool)
          {
              _increaseAllowance(msg.sender, spender, increment);
              return true;
          }
          /**
           * @inheritdoc FiatTokenV2
           */
          function decreaseAllowance(address spender, uint256 decrement)
              external
              override
              whenNotPaused
              returns (bool)
          {
              _decreaseAllowance(msg.sender, spender, decrement);
              return true;
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity >=0.6.2 <0.8.0;
      /**
       * @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
           * ====
           */
          function isContract(address account) internal view returns (bool) {
              // This method relies on extcodesize, which returns 0 for contracts in
              // construction, since the code is only stored at the end of the
              // constructor execution.
              uint256 size;
              // solhint-disable-next-line no-inline-assembly
              assembly { size := extcodesize(account) }
              return size > 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");
              // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
              (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");
              // solhint-disable-next-line avoid-low-level-calls
              (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");
              // solhint-disable-next-line avoid-low-level-calls
              (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");
              // solhint-disable-next-line avoid-low-level-calls
              (bool success, bytes memory returndata) = target.delegatecall(data);
              return _verifyCallResult(success, returndata, errorMessage);
          }
          function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private 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
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          let returndata_size := mload(returndata)
                          revert(add(32, returndata), returndata_size)
                      }
                  } else {
                      revert(errorMessage);
                  }
              }
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity >=0.6.0 <0.8.0;
      import "./IERC20.sol";
      import "../../math/SafeMath.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 SafeMath for uint256;
          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'
              // solhint-disable-next-line max-line-length
              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).add(value);
              _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
          }
          function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
              uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
              _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
                  // solhint-disable-next-line max-line-length
                  require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
              }
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity >=0.6.0 <0.8.0;
      /**
       * @dev Interface of the ERC20 standard as defined in the EIP.
       */
      interface IERC20 {
          /**
           * @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 `recipient`.
           *
           * Returns a boolean value indicating whether the operation succeeded.
           *
           * Emits a {Transfer} event.
           */
          function transfer(address recipient, 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 `sender` to `recipient` 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 sender, address recipient, uint256 amount) external returns (bool);
          /**
           * @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);
      }
      // SPDX-License-Identifier: MIT
      pragma solidity >=0.6.0 <0.8.0;
      /**
       * @dev Wrappers over Solidity's arithmetic operations with added overflow
       * checks.
       *
       * Arithmetic operations in Solidity wrap on overflow. This can easily result
       * in bugs, because programmers usually assume that an overflow raises an
       * error, which is the standard behavior in high level programming languages.
       * `SafeMath` restores this intuition by reverting the transaction when an
       * operation overflows.
       *
       * Using this library instead of the unchecked operations eliminates an entire
       * class of bugs, so it's recommended to use it always.
       */
      library SafeMath {
          /**
           * @dev Returns the addition of two unsigned integers, with an overflow flag.
           *
           * _Available since v3.4._
           */
          function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
              uint256 c = a + b;
              if (c < a) return (false, 0);
              return (true, c);
          }
          /**
           * @dev Returns the substraction of two unsigned integers, with an overflow flag.
           *
           * _Available since v3.4._
           */
          function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
              if (b > a) return (false, 0);
              return (true, a - b);
          }
          /**
           * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
           *
           * _Available since v3.4._
           */
          function tryMul(uint256 a, uint256 b) internal pure returns (bool, 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-contracts/pull/522
              if (a == 0) return (true, 0);
              uint256 c = a * b;
              if (c / a != b) return (false, 0);
              return (true, c);
          }
          /**
           * @dev Returns the division of two unsigned integers, with a division by zero flag.
           *
           * _Available since v3.4._
           */
          function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
              if (b == 0) return (false, 0);
              return (true, a / b);
          }
          /**
           * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
           *
           * _Available since v3.4._
           */
          function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
              if (b == 0) return (false, 0);
              return (true, a % b);
          }
          /**
           * @dev Returns the addition of two unsigned integers, reverting on
           * overflow.
           *
           * Counterpart to Solidity's `+` operator.
           *
           * Requirements:
           *
           * - Addition cannot overflow.
           */
          function add(uint256 a, uint256 b) internal pure returns (uint256) {
              uint256 c = a + b;
              require(c >= a, "SafeMath: addition overflow");
              return c;
          }
          /**
           * @dev Returns the subtraction of two unsigned integers, reverting on
           * overflow (when the result is negative).
           *
           * Counterpart to Solidity's `-` operator.
           *
           * Requirements:
           *
           * - Subtraction cannot overflow.
           */
          function sub(uint256 a, uint256 b) internal pure returns (uint256) {
              require(b <= a, "SafeMath: subtraction overflow");
              return a - b;
          }
          /**
           * @dev Returns the multiplication of two unsigned integers, reverting on
           * overflow.
           *
           * Counterpart to Solidity's `*` operator.
           *
           * Requirements:
           *
           * - Multiplication cannot overflow.
           */
          function mul(uint256 a, uint256 b) internal pure returns (uint256) {
              if (a == 0) return 0;
              uint256 c = a * b;
              require(c / a == b, "SafeMath: multiplication overflow");
              return c;
          }
          /**
           * @dev Returns the integer division of two unsigned integers, reverting on
           * division by zero. The result is rounded towards zero.
           *
           * Counterpart to Solidity's `/` operator. Note: this function uses a
           * `revert` opcode (which leaves remaining gas untouched) while Solidity
           * uses an invalid opcode to revert (consuming all remaining gas).
           *
           * Requirements:
           *
           * - The divisor cannot be zero.
           */
          function div(uint256 a, uint256 b) internal pure returns (uint256) {
              require(b > 0, "SafeMath: division by zero");
              return a / b;
          }
          /**
           * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
           * reverting when dividing by zero.
           *
           * Counterpart to Solidity's `%` operator. This function uses a `revert`
           * opcode (which leaves remaining gas untouched) while Solidity uses an
           * invalid opcode to revert (consuming all remaining gas).
           *
           * Requirements:
           *
           * - The divisor cannot be zero.
           */
          function mod(uint256 a, uint256 b) internal pure returns (uint256) {
              require(b > 0, "SafeMath: modulo by zero");
              return a % b;
          }
          /**
           * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
           * overflow (when the result is negative).
           *
           * CAUTION: This function is deprecated because it requires allocating memory for the error
           * message unnecessarily. For custom revert reasons use {trySub}.
           *
           * Counterpart to Solidity's `-` operator.
           *
           * Requirements:
           *
           * - Subtraction cannot overflow.
           */
          function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
              require(b <= a, errorMessage);
              return a - b;
          }
          /**
           * @dev Returns the integer division of two unsigned integers, reverting with custom message on
           * division by zero. The result is rounded towards zero.
           *
           * CAUTION: This function is deprecated because it requires allocating memory for the error
           * message unnecessarily. For custom revert reasons use {tryDiv}.
           *
           * Counterpart to Solidity's `/` operator. Note: this function uses a
           * `revert` opcode (which leaves remaining gas untouched) while Solidity
           * uses an invalid opcode to revert (consuming all remaining gas).
           *
           * Requirements:
           *
           * - The divisor cannot be zero.
           */
          function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
              require(b > 0, errorMessage);
              return a / b;
          }
          /**
           * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
           * reverting with custom message when dividing by zero.
           *
           * CAUTION: This function is deprecated because it requires allocating memory for the error
           * message unnecessarily. For custom revert reasons use {tryMod}.
           *
           * Counterpart to Solidity's `%` operator. This function uses a `revert`
           * opcode (which leaves remaining gas untouched) while Solidity uses an
           * invalid opcode to revert (consuming all remaining gas).
           *
           * Requirements:
           *
           * - The divisor cannot be zero.
           */
          function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
              require(b > 0, errorMessage);
              return a % b;
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * Licensed under the Apache License, Version 2.0 (the "License");
       * you may not use this file except in compliance with the License.
       * You may obtain a copy of the License at
       *
       * http://www.apache.org/licenses/LICENSE-2.0
       *
       * Unless required by applicable law or agreed to in writing, software
       * distributed under the License is distributed on an "AS IS" BASIS,
       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
       * See the License for the specific language governing permissions and
       * limitations under the License.
       */
      pragma solidity 0.6.12;
      import { FiatTokenV2 } from "./FiatTokenV2.sol";
      // solhint-disable func-name-mixedcase
      /**
       * @title FiatToken V2.1
       * @notice ERC20 Token backed by fiat reserves, version 2.1
       */
      contract FiatTokenV2_1 is FiatTokenV2 {
          /**
           * @notice Initialize v2.1
           * @param lostAndFound  The address to which the locked funds are sent
           */
          function initializeV2_1(address lostAndFound) external {
              // solhint-disable-next-line reason-string
              require(_initializedVersion == 1);
              uint256 lockedAmount = _balanceOf(address(this));
              if (lockedAmount > 0) {
                  _transfer(address(this), lostAndFound, lockedAmount);
              }
              _blacklist(address(this));
              _initializedVersion = 2;
          }
          /**
           * @notice Version string for the EIP712 domain separator
           * @return Version string
           */
          function version() external pure returns (string memory) {
              return "2";
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * Licensed under the Apache License, Version 2.0 (the "License");
       * you may not use this file except in compliance with the License.
       * You may obtain a copy of the License at
       *
       * http://www.apache.org/licenses/LICENSE-2.0
       *
       * Unless required by applicable law or agreed to in writing, software
       * distributed under the License is distributed on an "AS IS" BASIS,
       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
       * See the License for the specific language governing permissions and
       * limitations under the License.
       */
      pragma solidity 0.6.12;
      import { FiatTokenV1_1 } from "../v1.1/FiatTokenV1_1.sol";
      import { EIP712 } from "../util/EIP712.sol";
      import { EIP3009 } from "./EIP3009.sol";
      import { EIP2612 } from "./EIP2612.sol";
      /**
       * @title FiatToken V2
       * @notice ERC20 Token backed by fiat reserves, version 2
       */
      contract FiatTokenV2 is FiatTokenV1_1, EIP3009, EIP2612 {
          uint8 internal _initializedVersion;
          /**
           * @notice Initialize v2
           * @param newName   New token name
           */
          function initializeV2(string calldata newName) external {
              // solhint-disable-next-line reason-string
              require(initialized && _initializedVersion == 0);
              name = newName;
              _DEPRECATED_CACHED_DOMAIN_SEPARATOR = EIP712.makeDomainSeparator(
                  newName,
                  "2"
              );
              _initializedVersion = 1;
          }
          /**
           * @notice Increase the allowance by a given increment
           * @param spender   Spender's address
           * @param increment Amount of increase in allowance
           * @return True if successful
           */
          function increaseAllowance(address spender, uint256 increment)
              external
              virtual
              whenNotPaused
              notBlacklisted(msg.sender)
              notBlacklisted(spender)
              returns (bool)
          {
              _increaseAllowance(msg.sender, spender, increment);
              return true;
          }
          /**
           * @notice Decrease the allowance by a given decrement
           * @param spender   Spender's address
           * @param decrement Amount of decrease in allowance
           * @return True if successful
           */
          function decreaseAllowance(address spender, uint256 decrement)
              external
              virtual
              whenNotPaused
              notBlacklisted(msg.sender)
              notBlacklisted(spender)
              returns (bool)
          {
              _decreaseAllowance(msg.sender, spender, decrement);
              return true;
          }
          /**
           * @notice Execute a transfer with a signed authorization
           * @param from          Payer's address (Authorizer)
           * @param to            Payee's address
           * @param value         Amount to be transferred
           * @param validAfter    The time after which this is valid (unix time)
           * @param validBefore   The time before which this is valid (unix time)
           * @param nonce         Unique nonce
           * @param v             v of the signature
           * @param r             r of the signature
           * @param s             s of the signature
           */
          function transferWithAuthorization(
              address from,
              address to,
              uint256 value,
              uint256 validAfter,
              uint256 validBefore,
              bytes32 nonce,
              uint8 v,
              bytes32 r,
              bytes32 s
          ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
              _transferWithAuthorization(
                  from,
                  to,
                  value,
                  validAfter,
                  validBefore,
                  nonce,
                  v,
                  r,
                  s
              );
          }
          /**
           * @notice Receive a transfer with a signed authorization from the payer
           * @dev This has an additional check to ensure that the payee's address
           * matches the caller of this function to prevent front-running attacks.
           * @param from          Payer's address (Authorizer)
           * @param to            Payee's address
           * @param value         Amount to be transferred
           * @param validAfter    The time after which this is valid (unix time)
           * @param validBefore   The time before which this is valid (unix time)
           * @param nonce         Unique nonce
           * @param v             v of the signature
           * @param r             r of the signature
           * @param s             s of the signature
           */
          function receiveWithAuthorization(
              address from,
              address to,
              uint256 value,
              uint256 validAfter,
              uint256 validBefore,
              bytes32 nonce,
              uint8 v,
              bytes32 r,
              bytes32 s
          ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
              _receiveWithAuthorization(
                  from,
                  to,
                  value,
                  validAfter,
                  validBefore,
                  nonce,
                  v,
                  r,
                  s
              );
          }
          /**
           * @notice Attempt to cancel an authorization
           * @dev Works only if the authorization is not yet used.
           * @param authorizer    Authorizer's address
           * @param nonce         Nonce of the authorization
           * @param v             v of the signature
           * @param r             r of the signature
           * @param s             s of the signature
           */
          function cancelAuthorization(
              address authorizer,
              bytes32 nonce,
              uint8 v,
              bytes32 r,
              bytes32 s
          ) external whenNotPaused {
              _cancelAuthorization(authorizer, nonce, v, r, s);
          }
          /**
           * @notice Update allowance with a signed permit
           * @param owner       Token owner's address (Authorizer)
           * @param spender     Spender's address
           * @param value       Amount of allowance
           * @param deadline    The time at which the signature expires (unix time), or max uint256 value to signal no expiration
           * @param v           v of the signature
           * @param r           r of the signature
           * @param s           s of the signature
           */
          function permit(
              address owner,
              address spender,
              uint256 value,
              uint256 deadline,
              uint8 v,
              bytes32 r,
              bytes32 s
          )
              external
              virtual
              whenNotPaused
              notBlacklisted(owner)
              notBlacklisted(spender)
          {
              _permit(owner, spender, value, deadline, v, r, s);
          }
          /**
           * @dev Internal function to increase the allowance by a given increment
           * @param owner     Token owner's address
           * @param spender   Spender's address
           * @param increment Amount of increase
           */
          function _increaseAllowance(
              address owner,
              address spender,
              uint256 increment
          ) internal override {
              _approve(owner, spender, allowed[owner][spender].add(increment));
          }
          /**
           * @dev Internal function to decrease the allowance by a given decrement
           * @param owner     Token owner's address
           * @param spender   Spender's address
           * @param decrement Amount of decrease
           */
          function _decreaseAllowance(
              address owner,
              address spender,
              uint256 decrement
          ) internal override {
              _approve(
                  owner,
                  spender,
                  allowed[owner][spender].sub(
                      decrement,
                      "ERC20: decreased allowance below zero"
                  )
              );
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * Licensed under the Apache License, Version 2.0 (the "License");
       * you may not use this file except in compliance with the License.
       * You may obtain a copy of the License at
       *
       * http://www.apache.org/licenses/LICENSE-2.0
       *
       * Unless required by applicable law or agreed to in writing, software
       * distributed under the License is distributed on an "AS IS" BASIS,
       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
       * See the License for the specific language governing permissions and
       * limitations under the License.
       */
      pragma solidity 0.6.12;
      // solhint-disable func-name-mixedcase
      /**
       * @title EIP712 Domain
       */
      contract EIP712Domain {
          // was originally DOMAIN_SEPARATOR
          // but that has been moved to a method so we can override it in V2_2+
          bytes32 internal _DEPRECATED_CACHED_DOMAIN_SEPARATOR;
          /**
           * @notice Get the EIP712 Domain Separator.
           * @return The bytes32 EIP712 domain separator.
           */
          function DOMAIN_SEPARATOR() external view returns (bytes32) {
              return _domainSeparator();
          }
          /**
           * @dev Internal method to get the EIP712 Domain Separator.
           * @return The bytes32 EIP712 domain separator.
           */
          function _domainSeparator() internal virtual view returns (bytes32) {
              return _DEPRECATED_CACHED_DOMAIN_SEPARATOR;
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * Licensed under the Apache License, Version 2.0 (the "License");
       * you may not use this file except in compliance with the License.
       * You may obtain a copy of the License at
       *
       * http://www.apache.org/licenses/LICENSE-2.0
       *
       * Unless required by applicable law or agreed to in writing, software
       * distributed under the License is distributed on an "AS IS" BASIS,
       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
       * See the License for the specific language governing permissions and
       * limitations under the License.
       */
      pragma solidity 0.6.12;
      import { AbstractFiatTokenV2 } from "./AbstractFiatTokenV2.sol";
      import { EIP712Domain } from "./EIP712Domain.sol";
      import { SignatureChecker } from "../util/SignatureChecker.sol";
      import { MessageHashUtils } from "../util/MessageHashUtils.sol";
      /**
       * @title EIP-3009
       * @notice Provide internal implementation for gas-abstracted transfers
       * @dev Contracts that inherit from this must wrap these with publicly
       * accessible functions, optionally adding modifiers where necessary
       */
      abstract contract EIP3009 is AbstractFiatTokenV2, EIP712Domain {
          // keccak256("TransferWithAuthorization(address from,address to,uint256 value,uint256 validAfter,uint256 validBefore,bytes32 nonce)")
          bytes32
              public constant TRANSFER_WITH_AUTHORIZATION_TYPEHASH = 0x7c7c6cdb67a18743f49ec6fa9b35f50d52ed05cbed4cc592e13b44501c1a2267;
          // keccak256("ReceiveWithAuthorization(address from,address to,uint256 value,uint256 validAfter,uint256 validBefore,bytes32 nonce)")
          bytes32
              public constant RECEIVE_WITH_AUTHORIZATION_TYPEHASH = 0xd099cc98ef71107a616c4f0f941f04c322d8e254fe26b3c6668db87aae413de8;
          // keccak256("CancelAuthorization(address authorizer,bytes32 nonce)")
          bytes32
              public constant CANCEL_AUTHORIZATION_TYPEHASH = 0x158b0a9edf7a828aad02f63cd515c68ef2f50ba807396f6d12842833a1597429;
          /**
           * @dev authorizer address => nonce => bool (true if nonce is used)
           */
          mapping(address => mapping(bytes32 => bool)) private _authorizationStates;
          event AuthorizationUsed(address indexed authorizer, bytes32 indexed nonce);
          event AuthorizationCanceled(
              address indexed authorizer,
              bytes32 indexed nonce
          );
          /**
           * @notice Returns the state of an authorization
           * @dev Nonces are randomly generated 32-byte data unique to the
           * authorizer's address
           * @param authorizer    Authorizer's address
           * @param nonce         Nonce of the authorization
           * @return True if the nonce is used
           */
          function authorizationState(address authorizer, bytes32 nonce)
              external
              view
              returns (bool)
          {
              return _authorizationStates[authorizer][nonce];
          }
          /**
           * @notice Execute a transfer with a signed authorization
           * @param from          Payer's address (Authorizer)
           * @param to            Payee's address
           * @param value         Amount to be transferred
           * @param validAfter    The time after which this is valid (unix time)
           * @param validBefore   The time before which this is valid (unix time)
           * @param nonce         Unique nonce
           * @param v             v of the signature
           * @param r             r of the signature
           * @param s             s of the signature
           */
          function _transferWithAuthorization(
              address from,
              address to,
              uint256 value,
              uint256 validAfter,
              uint256 validBefore,
              bytes32 nonce,
              uint8 v,
              bytes32 r,
              bytes32 s
          ) internal {
              _transferWithAuthorization(
                  from,
                  to,
                  value,
                  validAfter,
                  validBefore,
                  nonce,
                  abi.encodePacked(r, s, v)
              );
          }
          /**
           * @notice Execute a transfer with a signed authorization
           * @dev EOA wallet signatures should be packed in the order of r, s, v.
           * @param from          Payer's address (Authorizer)
           * @param to            Payee's address
           * @param value         Amount to be transferred
           * @param validAfter    The time after which this is valid (unix time)
           * @param validBefore   The time before which this is valid (unix time)
           * @param nonce         Unique nonce
           * @param signature     Signature byte array produced by an EOA wallet or a contract wallet
           */
          function _transferWithAuthorization(
              address from,
              address to,
              uint256 value,
              uint256 validAfter,
              uint256 validBefore,
              bytes32 nonce,
              bytes memory signature
          ) internal {
              _requireValidAuthorization(from, nonce, validAfter, validBefore);
              _requireValidSignature(
                  from,
                  keccak256(
                      abi.encode(
                          TRANSFER_WITH_AUTHORIZATION_TYPEHASH,
                          from,
                          to,
                          value,
                          validAfter,
                          validBefore,
                          nonce
                      )
                  ),
                  signature
              );
              _markAuthorizationAsUsed(from, nonce);
              _transfer(from, to, value);
          }
          /**
           * @notice Receive a transfer with a signed authorization from the payer
           * @dev This has an additional check to ensure that the payee's address
           * matches the caller of this function to prevent front-running attacks.
           * @param from          Payer's address (Authorizer)
           * @param to            Payee's address
           * @param value         Amount to be transferred
           * @param validAfter    The time after which this is valid (unix time)
           * @param validBefore   The time before which this is valid (unix time)
           * @param nonce         Unique nonce
           * @param v             v of the signature
           * @param r             r of the signature
           * @param s             s of the signature
           */
          function _receiveWithAuthorization(
              address from,
              address to,
              uint256 value,
              uint256 validAfter,
              uint256 validBefore,
              bytes32 nonce,
              uint8 v,
              bytes32 r,
              bytes32 s
          ) internal {
              _receiveWithAuthorization(
                  from,
                  to,
                  value,
                  validAfter,
                  validBefore,
                  nonce,
                  abi.encodePacked(r, s, v)
              );
          }
          /**
           * @notice Receive a transfer with a signed authorization from the payer
           * @dev This has an additional check to ensure that the payee's address
           * matches the caller of this function to prevent front-running attacks.
           * EOA wallet signatures should be packed in the order of r, s, v.
           * @param from          Payer's address (Authorizer)
           * @param to            Payee's address
           * @param value         Amount to be transferred
           * @param validAfter    The time after which this is valid (unix time)
           * @param validBefore   The time before which this is valid (unix time)
           * @param nonce         Unique nonce
           * @param signature     Signature byte array produced by an EOA wallet or a contract wallet
           */
          function _receiveWithAuthorization(
              address from,
              address to,
              uint256 value,
              uint256 validAfter,
              uint256 validBefore,
              bytes32 nonce,
              bytes memory signature
          ) internal {
              require(to == msg.sender, "FiatTokenV2: caller must be the payee");
              _requireValidAuthorization(from, nonce, validAfter, validBefore);
              _requireValidSignature(
                  from,
                  keccak256(
                      abi.encode(
                          RECEIVE_WITH_AUTHORIZATION_TYPEHASH,
                          from,
                          to,
                          value,
                          validAfter,
                          validBefore,
                          nonce
                      )
                  ),
                  signature
              );
              _markAuthorizationAsUsed(from, nonce);
              _transfer(from, to, value);
          }
          /**
           * @notice Attempt to cancel an authorization
           * @param authorizer    Authorizer's address
           * @param nonce         Nonce of the authorization
           * @param v             v of the signature
           * @param r             r of the signature
           * @param s             s of the signature
           */
          function _cancelAuthorization(
              address authorizer,
              bytes32 nonce,
              uint8 v,
              bytes32 r,
              bytes32 s
          ) internal {
              _cancelAuthorization(authorizer, nonce, abi.encodePacked(r, s, v));
          }
          /**
           * @notice Attempt to cancel an authorization
           * @dev EOA wallet signatures should be packed in the order of r, s, v.
           * @param authorizer    Authorizer's address
           * @param nonce         Nonce of the authorization
           * @param signature     Signature byte array produced by an EOA wallet or a contract wallet
           */
          function _cancelAuthorization(
              address authorizer,
              bytes32 nonce,
              bytes memory signature
          ) internal {
              _requireUnusedAuthorization(authorizer, nonce);
              _requireValidSignature(
                  authorizer,
                  keccak256(
                      abi.encode(CANCEL_AUTHORIZATION_TYPEHASH, authorizer, nonce)
                  ),
                  signature
              );
              _authorizationStates[authorizer][nonce] = true;
              emit AuthorizationCanceled(authorizer, nonce);
          }
          /**
           * @notice Validates that signature against input data struct
           * @param signer        Signer's address
           * @param dataHash      Hash of encoded data struct
           * @param signature     Signature byte array produced by an EOA wallet or a contract wallet
           */
          function _requireValidSignature(
              address signer,
              bytes32 dataHash,
              bytes memory signature
          ) private view {
              require(
                  SignatureChecker.isValidSignatureNow(
                      signer,
                      MessageHashUtils.toTypedDataHash(_domainSeparator(), dataHash),
                      signature
                  ),
                  "FiatTokenV2: invalid signature"
              );
          }
          /**
           * @notice Check that an authorization is unused
           * @param authorizer    Authorizer's address
           * @param nonce         Nonce of the authorization
           */
          function _requireUnusedAuthorization(address authorizer, bytes32 nonce)
              private
              view
          {
              require(
                  !_authorizationStates[authorizer][nonce],
                  "FiatTokenV2: authorization is used or canceled"
              );
          }
          /**
           * @notice Check that authorization is valid
           * @param authorizer    Authorizer's address
           * @param nonce         Nonce of the authorization
           * @param validAfter    The time after which this is valid (unix time)
           * @param validBefore   The time before which this is valid (unix time)
           */
          function _requireValidAuthorization(
              address authorizer,
              bytes32 nonce,
              uint256 validAfter,
              uint256 validBefore
          ) private view {
              require(
                  now > validAfter,
                  "FiatTokenV2: authorization is not yet valid"
              );
              require(now < validBefore, "FiatTokenV2: authorization is expired");
              _requireUnusedAuthorization(authorizer, nonce);
          }
          /**
           * @notice Mark an authorization as used
           * @param authorizer    Authorizer's address
           * @param nonce         Nonce of the authorization
           */
          function _markAuthorizationAsUsed(address authorizer, bytes32 nonce)
              private
          {
              _authorizationStates[authorizer][nonce] = true;
              emit AuthorizationUsed(authorizer, nonce);
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * Licensed under the Apache License, Version 2.0 (the "License");
       * you may not use this file except in compliance with the License.
       * You may obtain a copy of the License at
       *
       * http://www.apache.org/licenses/LICENSE-2.0
       *
       * Unless required by applicable law or agreed to in writing, software
       * distributed under the License is distributed on an "AS IS" BASIS,
       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
       * See the License for the specific language governing permissions and
       * limitations under the License.
       */
      pragma solidity 0.6.12;
      import { AbstractFiatTokenV2 } from "./AbstractFiatTokenV2.sol";
      import { EIP712Domain } from "./EIP712Domain.sol";
      import { MessageHashUtils } from "../util/MessageHashUtils.sol";
      import { SignatureChecker } from "../util/SignatureChecker.sol";
      /**
       * @title EIP-2612
       * @notice Provide internal implementation for gas-abstracted approvals
       */
      abstract contract EIP2612 is AbstractFiatTokenV2, EIP712Domain {
          // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)")
          bytes32
              public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
          mapping(address => uint256) private _permitNonces;
          /**
           * @notice Nonces for permit
           * @param owner Token owner's address (Authorizer)
           * @return Next nonce
           */
          function nonces(address owner) external view returns (uint256) {
              return _permitNonces[owner];
          }
          /**
           * @notice Verify a signed approval permit and execute if valid
           * @param owner     Token owner's address (Authorizer)
           * @param spender   Spender's address
           * @param value     Amount of allowance
           * @param deadline  The time at which the signature expires (unix time), or max uint256 value to signal no expiration
           * @param v         v of the signature
           * @param r         r of the signature
           * @param s         s of the signature
           */
          function _permit(
              address owner,
              address spender,
              uint256 value,
              uint256 deadline,
              uint8 v,
              bytes32 r,
              bytes32 s
          ) internal {
              _permit(owner, spender, value, deadline, abi.encodePacked(r, s, v));
          }
          /**
           * @notice Verify a signed approval permit and execute if valid
           * @dev EOA wallet signatures should be packed in the order of r, s, v.
           * @param owner      Token owner's address (Authorizer)
           * @param spender    Spender's address
           * @param value      Amount of allowance
           * @param deadline   The time at which the signature expires (unix time), or max uint256 value to signal no expiration
           * @param signature  Signature byte array signed by an EOA wallet or a contract wallet
           */
          function _permit(
              address owner,
              address spender,
              uint256 value,
              uint256 deadline,
              bytes memory signature
          ) internal {
              require(
                  deadline == type(uint256).max || deadline >= now,
                  "FiatTokenV2: permit is expired"
              );
              bytes32 typedDataHash = MessageHashUtils.toTypedDataHash(
                  _domainSeparator(),
                  keccak256(
                      abi.encode(
                          PERMIT_TYPEHASH,
                          owner,
                          spender,
                          value,
                          _permitNonces[owner]++,
                          deadline
                      )
                  )
              );
              require(
                  SignatureChecker.isValidSignatureNow(
                      owner,
                      typedDataHash,
                      signature
                  ),
                  "EIP2612: invalid signature"
              );
              _approve(owner, spender, value);
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * Licensed under the Apache License, Version 2.0 (the "License");
       * you may not use this file except in compliance with the License.
       * You may obtain a copy of the License at
       *
       * http://www.apache.org/licenses/LICENSE-2.0
       *
       * Unless required by applicable law or agreed to in writing, software
       * distributed under the License is distributed on an "AS IS" BASIS,
       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
       * See the License for the specific language governing permissions and
       * limitations under the License.
       */
      pragma solidity 0.6.12;
      import { AbstractFiatTokenV1 } from "../v1/AbstractFiatTokenV1.sol";
      abstract contract AbstractFiatTokenV2 is AbstractFiatTokenV1 {
          function _increaseAllowance(
              address owner,
              address spender,
              uint256 increment
          ) internal virtual;
          function _decreaseAllowance(
              address owner,
              address spender,
              uint256 decrement
          ) internal virtual;
      }
      /**
       * SPDX-License-Identifier: MIT
       *
       * Copyright (c) 2016 Smart Contract Solutions, Inc.
       * Copyright (c) 2018-2020 CENTRE SECZ
       *
       * Permission is hereby granted, free of charge, to any person obtaining a copy
       * of this software and associated documentation files (the "Software"), to deal
       * in the Software without restriction, including without limitation the rights
       * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
       * copies of the Software, and to permit persons to whom the Software is
       * furnished to do so, subject to the following conditions:
       *
       * The above copyright notice and this permission notice shall be included in
       * copies or substantial portions of the Software.
       *
       * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
       * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
       * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
       * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
       * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
       * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
       * SOFTWARE.
       */
      pragma solidity 0.6.12;
      import { Ownable } from "./Ownable.sol";
      /**
       * @notice Base contract which allows children to implement an emergency stop
       * mechanism
       * @dev Forked from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/feb665136c0dae9912e08397c1a21c4af3651ef3/contracts/lifecycle/Pausable.sol
       * Modifications:
       * 1. Added pauser role, switched pause/unpause to be onlyPauser (6/14/2018)
       * 2. Removed whenNotPause/whenPaused from pause/unpause (6/14/2018)
       * 3. Removed whenPaused (6/14/2018)
       * 4. Switches ownable library to use ZeppelinOS (7/12/18)
       * 5. Remove constructor (7/13/18)
       * 6. Reformat, conform to Solidity 0.6 syntax and add error messages (5/13/20)
       * 7. Make public functions external (5/27/20)
       */
      contract Pausable is Ownable {
          event Pause();
          event Unpause();
          event PauserChanged(address indexed newAddress);
          address public pauser;
          bool public paused = false;
          /**
           * @dev Modifier to make a function callable only when the contract is not paused.
           */
          modifier whenNotPaused() {
              require(!paused, "Pausable: paused");
              _;
          }
          /**
           * @dev throws if called by any account other than the pauser
           */
          modifier onlyPauser() {
              require(msg.sender == pauser, "Pausable: caller is not the pauser");
              _;
          }
          /**
           * @dev called by the owner to pause, triggers stopped state
           */
          function pause() external onlyPauser {
              paused = true;
              emit Pause();
          }
          /**
           * @dev called by the owner to unpause, returns to normal state
           */
          function unpause() external onlyPauser {
              paused = false;
              emit Unpause();
          }
          /**
           * @notice Updates the pauser address.
           * @param _newPauser The address of the new pauser.
           */
          function updatePauser(address _newPauser) external onlyOwner {
              require(
                  _newPauser != address(0),
                  "Pausable: new pauser is the zero address"
              );
              pauser = _newPauser;
              emit PauserChanged(pauser);
          }
      }
      /**
       * SPDX-License-Identifier: MIT
       *
       * Copyright (c) 2018 zOS Global Limited.
       * Copyright (c) 2018-2020 CENTRE SECZ
       *
       * Permission is hereby granted, free of charge, to any person obtaining a copy
       * of this software and associated documentation files (the "Software"), to deal
       * in the Software without restriction, including without limitation the rights
       * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
       * copies of the Software, and to permit persons to whom the Software is
       * furnished to do so, subject to the following conditions:
       *
       * The above copyright notice and this permission notice shall be included in
       * copies or substantial portions of the Software.
       *
       * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
       * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
       * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
       * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
       * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
       * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
       * SOFTWARE.
       */
      pragma solidity 0.6.12;
      /**
       * @notice The Ownable contract has an owner address, and provides basic
       * authorization control functions
       * @dev Forked from https://github.com/OpenZeppelin/openzeppelin-labs/blob/3887ab77b8adafba4a26ace002f3a684c1a3388b/upgradeability_ownership/contracts/ownership/Ownable.sol
       * Modifications:
       * 1. Consolidate OwnableStorage into this contract (7/13/18)
       * 2. Reformat, conform to Solidity 0.6 syntax, and add error messages (5/13/20)
       * 3. Make public functions external (5/27/20)
       */
      contract Ownable {
          // Owner of the contract
          address private _owner;
          /**
           * @dev Event to show ownership has been transferred
           * @param previousOwner representing the address of the previous owner
           * @param newOwner representing the address of the new owner
           */
          event OwnershipTransferred(address previousOwner, address newOwner);
          /**
           * @dev The constructor sets the original owner of the contract to the sender account.
           */
          constructor() public {
              setOwner(msg.sender);
          }
          /**
           * @dev Tells the address of the owner
           * @return the address of the owner
           */
          function owner() external view returns (address) {
              return _owner;
          }
          /**
           * @dev Sets a new owner address
           */
          function setOwner(address newOwner) internal {
              _owner = newOwner;
          }
          /**
           * @dev Throws if called by any account other than the owner.
           */
          modifier onlyOwner() {
              require(msg.sender == _owner, "Ownable: caller is not the owner");
              _;
          }
          /**
           * @dev Allows the current owner to transfer control of the contract to a newOwner.
           * @param newOwner The address to transfer ownership to.
           */
          function transferOwnership(address newOwner) external onlyOwner {
              require(
                  newOwner != address(0),
                  "Ownable: new owner is the zero address"
              );
              emit OwnershipTransferred(_owner, newOwner);
              setOwner(newOwner);
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * Licensed under the Apache License, Version 2.0 (the "License");
       * you may not use this file except in compliance with the License.
       * You may obtain a copy of the License at
       *
       * http://www.apache.org/licenses/LICENSE-2.0
       *
       * Unless required by applicable law or agreed to in writing, software
       * distributed under the License is distributed on an "AS IS" BASIS,
       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
       * See the License for the specific language governing permissions and
       * limitations under the License.
       */
      pragma solidity 0.6.12;
      import { SafeMath } from "@openzeppelin/contracts/math/SafeMath.sol";
      import { AbstractFiatTokenV1 } from "./AbstractFiatTokenV1.sol";
      import { Ownable } from "./Ownable.sol";
      import { Pausable } from "./Pausable.sol";
      import { Blacklistable } from "./Blacklistable.sol";
      /**
       * @title FiatToken
       * @dev ERC20 Token backed by fiat reserves
       */
      contract FiatTokenV1 is AbstractFiatTokenV1, Ownable, Pausable, Blacklistable {
          using SafeMath for uint256;
          string public name;
          string public symbol;
          uint8 public decimals;
          string public currency;
          address public masterMinter;
          bool internal initialized;
          /// @dev A mapping that stores the balance and blacklist states for a given address.
          /// The first bit defines whether the address is blacklisted (1 if blacklisted, 0 otherwise).
          /// The last 255 bits define the balance for the address.
          mapping(address => uint256) internal balanceAndBlacklistStates;
          mapping(address => mapping(address => uint256)) internal allowed;
          uint256 internal totalSupply_ = 0;
          mapping(address => bool) internal minters;
          mapping(address => uint256) internal minterAllowed;
          event Mint(address indexed minter, address indexed to, uint256 amount);
          event Burn(address indexed burner, uint256 amount);
          event MinterConfigured(address indexed minter, uint256 minterAllowedAmount);
          event MinterRemoved(address indexed oldMinter);
          event MasterMinterChanged(address indexed newMasterMinter);
          /**
           * @notice Initializes the fiat token contract.
           * @param tokenName       The name of the fiat token.
           * @param tokenSymbol     The symbol of the fiat token.
           * @param tokenCurrency   The fiat currency that the token represents.
           * @param tokenDecimals   The number of decimals that the token uses.
           * @param newMasterMinter The masterMinter address for the fiat token.
           * @param newPauser       The pauser address for the fiat token.
           * @param newBlacklister  The blacklister address for the fiat token.
           * @param newOwner        The owner of the fiat token.
           */
          function initialize(
              string memory tokenName,
              string memory tokenSymbol,
              string memory tokenCurrency,
              uint8 tokenDecimals,
              address newMasterMinter,
              address newPauser,
              address newBlacklister,
              address newOwner
          ) public {
              require(!initialized, "FiatToken: contract is already initialized");
              require(
                  newMasterMinter != address(0),
                  "FiatToken: new masterMinter is the zero address"
              );
              require(
                  newPauser != address(0),
                  "FiatToken: new pauser is the zero address"
              );
              require(
                  newBlacklister != address(0),
                  "FiatToken: new blacklister is the zero address"
              );
              require(
                  newOwner != address(0),
                  "FiatToken: new owner is the zero address"
              );
              name = tokenName;
              symbol = tokenSymbol;
              currency = tokenCurrency;
              decimals = tokenDecimals;
              masterMinter = newMasterMinter;
              pauser = newPauser;
              blacklister = newBlacklister;
              setOwner(newOwner);
              initialized = true;
          }
          /**
           * @dev Throws if called by any account other than a minter.
           */
          modifier onlyMinters() {
              require(minters[msg.sender], "FiatToken: caller is not a minter");
              _;
          }
          /**
           * @notice Mints fiat tokens to an address.
           * @param _to The address that will receive the minted tokens.
           * @param _amount The amount of tokens to mint. Must be less than or equal
           * to the minterAllowance of the caller.
           * @return True if the operation was successful.
           */
          function mint(address _to, uint256 _amount)
              external
              whenNotPaused
              onlyMinters
              notBlacklisted(msg.sender)
              notBlacklisted(_to)
              returns (bool)
          {
              require(_to != address(0), "FiatToken: mint to the zero address");
              require(_amount > 0, "FiatToken: mint amount not greater than 0");
              uint256 mintingAllowedAmount = minterAllowed[msg.sender];
              require(
                  _amount <= mintingAllowedAmount,
                  "FiatToken: mint amount exceeds minterAllowance"
              );
              totalSupply_ = totalSupply_.add(_amount);
              _setBalance(_to, _balanceOf(_to).add(_amount));
              minterAllowed[msg.sender] = mintingAllowedAmount.sub(_amount);
              emit Mint(msg.sender, _to, _amount);
              emit Transfer(address(0), _to, _amount);
              return true;
          }
          /**
           * @dev Throws if called by any account other than the masterMinter
           */
          modifier onlyMasterMinter() {
              require(
                  msg.sender == masterMinter,
                  "FiatToken: caller is not the masterMinter"
              );
              _;
          }
          /**
           * @notice Gets the minter allowance for an account.
           * @param minter The address to check.
           * @return The remaining minter allowance for the account.
           */
          function minterAllowance(address minter) external view returns (uint256) {
              return minterAllowed[minter];
          }
          /**
           * @notice Checks if an account is a minter.
           * @param account The address to check.
           * @return True if the account is a minter, false if the account is not a minter.
           */
          function isMinter(address account) external view returns (bool) {
              return minters[account];
          }
          /**
           * @notice Gets the remaining amount of fiat tokens a spender is allowed to transfer on
           * behalf of the token owner.
           * @param owner   The token owner's address.
           * @param spender The spender's address.
           * @return The remaining allowance.
           */
          function allowance(address owner, address spender)
              external
              override
              view
              returns (uint256)
          {
              return allowed[owner][spender];
          }
          /**
           * @notice Gets the totalSupply of the fiat token.
           * @return The totalSupply of the fiat token.
           */
          function totalSupply() external override view returns (uint256) {
              return totalSupply_;
          }
          /**
           * @notice Gets the fiat token balance of an account.
           * @param account  The address to check.
           * @return balance The fiat token balance of the account.
           */
          function balanceOf(address account)
              external
              override
              view
              returns (uint256)
          {
              return _balanceOf(account);
          }
          /**
           * @notice Sets a fiat token allowance for a spender to spend on behalf of the caller.
           * @param spender The spender's address.
           * @param value   The allowance amount.
           * @return True if the operation was successful.
           */
          function approve(address spender, uint256 value)
              external
              virtual
              override
              whenNotPaused
              notBlacklisted(msg.sender)
              notBlacklisted(spender)
              returns (bool)
          {
              _approve(msg.sender, spender, value);
              return true;
          }
          /**
           * @dev Internal function to set allowance.
           * @param owner     Token owner's address.
           * @param spender   Spender's address.
           * @param value     Allowance amount.
           */
          function _approve(
              address owner,
              address spender,
              uint256 value
          ) internal override {
              require(owner != address(0), "ERC20: approve from the zero address");
              require(spender != address(0), "ERC20: approve to the zero address");
              allowed[owner][spender] = value;
              emit Approval(owner, spender, value);
          }
          /**
           * @notice Transfers tokens from an address to another by spending the caller's allowance.
           * @dev The caller must have some fiat token allowance on the payer's tokens.
           * @param from  Payer's address.
           * @param to    Payee's address.
           * @param value Transfer amount.
           * @return True if the operation was successful.
           */
          function transferFrom(
              address from,
              address to,
              uint256 value
          )
              external
              override
              whenNotPaused
              notBlacklisted(msg.sender)
              notBlacklisted(from)
              notBlacklisted(to)
              returns (bool)
          {
              require(
                  value <= allowed[from][msg.sender],
                  "ERC20: transfer amount exceeds allowance"
              );
              _transfer(from, to, value);
              allowed[from][msg.sender] = allowed[from][msg.sender].sub(value);
              return true;
          }
          /**
           * @notice Transfers tokens from the caller.
           * @param to    Payee's address.
           * @param value Transfer amount.
           * @return True if the operation was successful.
           */
          function transfer(address to, uint256 value)
              external
              override
              whenNotPaused
              notBlacklisted(msg.sender)
              notBlacklisted(to)
              returns (bool)
          {
              _transfer(msg.sender, to, value);
              return true;
          }
          /**
           * @dev Internal function to process transfers.
           * @param from  Payer's address.
           * @param to    Payee's address.
           * @param value Transfer amount.
           */
          function _transfer(
              address from,
              address to,
              uint256 value
          ) internal override {
              require(from != address(0), "ERC20: transfer from the zero address");
              require(to != address(0), "ERC20: transfer to the zero address");
              require(
                  value <= _balanceOf(from),
                  "ERC20: transfer amount exceeds balance"
              );
              _setBalance(from, _balanceOf(from).sub(value));
              _setBalance(to, _balanceOf(to).add(value));
              emit Transfer(from, to, value);
          }
          /**
           * @notice Adds or updates a new minter with a mint allowance.
           * @param minter The address of the minter.
           * @param minterAllowedAmount The minting amount allowed for the minter.
           * @return True if the operation was successful.
           */
          function configureMinter(address minter, uint256 minterAllowedAmount)
              external
              whenNotPaused
              onlyMasterMinter
              returns (bool)
          {
              minters[minter] = true;
              minterAllowed[minter] = minterAllowedAmount;
              emit MinterConfigured(minter, minterAllowedAmount);
              return true;
          }
          /**
           * @notice Removes a minter.
           * @param minter The address of the minter to remove.
           * @return True if the operation was successful.
           */
          function removeMinter(address minter)
              external
              onlyMasterMinter
              returns (bool)
          {
              minters[minter] = false;
              minterAllowed[minter] = 0;
              emit MinterRemoved(minter);
              return true;
          }
          /**
           * @notice Allows a minter to burn some of its own tokens.
           * @dev The caller must be a minter, must not be blacklisted, and the amount to burn
           * should be less than or equal to the account's balance.
           * @param _amount the amount of tokens to be burned.
           */
          function burn(uint256 _amount)
              external
              whenNotPaused
              onlyMinters
              notBlacklisted(msg.sender)
          {
              uint256 balance = _balanceOf(msg.sender);
              require(_amount > 0, "FiatToken: burn amount not greater than 0");
              require(balance >= _amount, "FiatToken: burn amount exceeds balance");
              totalSupply_ = totalSupply_.sub(_amount);
              _setBalance(msg.sender, balance.sub(_amount));
              emit Burn(msg.sender, _amount);
              emit Transfer(msg.sender, address(0), _amount);
          }
          /**
           * @notice Updates the master minter address.
           * @param _newMasterMinter The address of the new master minter.
           */
          function updateMasterMinter(address _newMasterMinter) external onlyOwner {
              require(
                  _newMasterMinter != address(0),
                  "FiatToken: new masterMinter is the zero address"
              );
              masterMinter = _newMasterMinter;
              emit MasterMinterChanged(masterMinter);
          }
          /**
           * @inheritdoc Blacklistable
           */
          function _blacklist(address _account) internal override {
              _setBlacklistState(_account, true);
          }
          /**
           * @inheritdoc Blacklistable
           */
          function _unBlacklist(address _account) internal override {
              _setBlacklistState(_account, false);
          }
          /**
           * @dev Helper method that sets the blacklist state of an account.
           * @param _account         The address of the account.
           * @param _shouldBlacklist True if the account should be blacklisted, false if the account should be unblacklisted.
           */
          function _setBlacklistState(address _account, bool _shouldBlacklist)
              internal
              virtual
          {
              _deprecatedBlacklisted[_account] = _shouldBlacklist;
          }
          /**
           * @dev Helper method that sets the balance of an account.
           * @param _account The address of the account.
           * @param _balance The new fiat token balance of the account.
           */
          function _setBalance(address _account, uint256 _balance) internal virtual {
              balanceAndBlacklistStates[_account] = _balance;
          }
          /**
           * @inheritdoc Blacklistable
           */
          function _isBlacklisted(address _account)
              internal
              virtual
              override
              view
              returns (bool)
          {
              return _deprecatedBlacklisted[_account];
          }
          /**
           * @dev Helper method to obtain the balance of an account.
           * @param _account  The address of the account.
           * @return          The fiat token balance of the account.
           */
          function _balanceOf(address _account)
              internal
              virtual
              view
              returns (uint256)
          {
              return balanceAndBlacklistStates[_account];
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * Licensed under the Apache License, Version 2.0 (the "License");
       * you may not use this file except in compliance with the License.
       * You may obtain a copy of the License at
       *
       * http://www.apache.org/licenses/LICENSE-2.0
       *
       * Unless required by applicable law or agreed to in writing, software
       * distributed under the License is distributed on an "AS IS" BASIS,
       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
       * See the License for the specific language governing permissions and
       * limitations under the License.
       */
      pragma solidity 0.6.12;
      import { Ownable } from "./Ownable.sol";
      /**
       * @title Blacklistable Token
       * @dev Allows accounts to be blacklisted by a "blacklister" role
       */
      abstract contract Blacklistable is Ownable {
          address public blacklister;
          mapping(address => bool) internal _deprecatedBlacklisted;
          event Blacklisted(address indexed _account);
          event UnBlacklisted(address indexed _account);
          event BlacklisterChanged(address indexed newBlacklister);
          /**
           * @dev Throws if called by any account other than the blacklister.
           */
          modifier onlyBlacklister() {
              require(
                  msg.sender == blacklister,
                  "Blacklistable: caller is not the blacklister"
              );
              _;
          }
          /**
           * @dev Throws if argument account is blacklisted.
           * @param _account The address to check.
           */
          modifier notBlacklisted(address _account) {
              require(
                  !_isBlacklisted(_account),
                  "Blacklistable: account is blacklisted"
              );
              _;
          }
          /**
           * @notice Checks if account is blacklisted.
           * @param _account The address to check.
           * @return True if the account is blacklisted, false if the account is not blacklisted.
           */
          function isBlacklisted(address _account) external view returns (bool) {
              return _isBlacklisted(_account);
          }
          /**
           * @notice Adds account to blacklist.
           * @param _account The address to blacklist.
           */
          function blacklist(address _account) external onlyBlacklister {
              _blacklist(_account);
              emit Blacklisted(_account);
          }
          /**
           * @notice Removes account from blacklist.
           * @param _account The address to remove from the blacklist.
           */
          function unBlacklist(address _account) external onlyBlacklister {
              _unBlacklist(_account);
              emit UnBlacklisted(_account);
          }
          /**
           * @notice Updates the blacklister address.
           * @param _newBlacklister The address of the new blacklister.
           */
          function updateBlacklister(address _newBlacklister) external onlyOwner {
              require(
                  _newBlacklister != address(0),
                  "Blacklistable: new blacklister is the zero address"
              );
              blacklister = _newBlacklister;
              emit BlacklisterChanged(blacklister);
          }
          /**
           * @dev Checks if account is blacklisted.
           * @param _account The address to check.
           * @return true if the account is blacklisted, false otherwise.
           */
          function _isBlacklisted(address _account)
              internal
              virtual
              view
              returns (bool);
          /**
           * @dev Helper method that blacklists an account.
           * @param _account The address to blacklist.
           */
          function _blacklist(address _account) internal virtual;
          /**
           * @dev Helper method that unblacklists an account.
           * @param _account The address to unblacklist.
           */
          function _unBlacklist(address _account) internal virtual;
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * Licensed under the Apache License, Version 2.0 (the "License");
       * you may not use this file except in compliance with the License.
       * You may obtain a copy of the License at
       *
       * http://www.apache.org/licenses/LICENSE-2.0
       *
       * Unless required by applicable law or agreed to in writing, software
       * distributed under the License is distributed on an "AS IS" BASIS,
       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
       * See the License for the specific language governing permissions and
       * limitations under the License.
       */
      pragma solidity 0.6.12;
      import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
      abstract contract AbstractFiatTokenV1 is IERC20 {
          function _approve(
              address owner,
              address spender,
              uint256 value
          ) internal virtual;
          function _transfer(
              address from,
              address to,
              uint256 value
          ) internal virtual;
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * Licensed under the Apache License, Version 2.0 (the "License");
       * you may not use this file except in compliance with the License.
       * You may obtain a copy of the License at
       *
       * http://www.apache.org/licenses/LICENSE-2.0
       *
       * Unless required by applicable law or agreed to in writing, software
       * distributed under the License is distributed on an "AS IS" BASIS,
       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
       * See the License for the specific language governing permissions and
       * limitations under the License.
       */
      pragma solidity 0.6.12;
      import { Ownable } from "../v1/Ownable.sol";
      import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
      import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
      contract Rescuable is Ownable {
          using SafeERC20 for IERC20;
          address private _rescuer;
          event RescuerChanged(address indexed newRescuer);
          /**
           * @notice Returns current rescuer
           * @return Rescuer's address
           */
          function rescuer() external view returns (address) {
              return _rescuer;
          }
          /**
           * @notice Revert if called by any account other than the rescuer.
           */
          modifier onlyRescuer() {
              require(msg.sender == _rescuer, "Rescuable: caller is not the rescuer");
              _;
          }
          /**
           * @notice Rescue ERC20 tokens locked up in this contract.
           * @param tokenContract ERC20 token contract address
           * @param to        Recipient address
           * @param amount    Amount to withdraw
           */
          function rescueERC20(
              IERC20 tokenContract,
              address to,
              uint256 amount
          ) external onlyRescuer {
              tokenContract.safeTransfer(to, amount);
          }
          /**
           * @notice Updates the rescuer address.
           * @param newRescuer The address of the new rescuer.
           */
          function updateRescuer(address newRescuer) external onlyOwner {
              require(
                  newRescuer != address(0),
                  "Rescuable: new rescuer is the zero address"
              );
              _rescuer = newRescuer;
              emit RescuerChanged(newRescuer);
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * Licensed under the Apache License, Version 2.0 (the "License");
       * you may not use this file except in compliance with the License.
       * You may obtain a copy of the License at
       *
       * http://www.apache.org/licenses/LICENSE-2.0
       *
       * Unless required by applicable law or agreed to in writing, software
       * distributed under the License is distributed on an "AS IS" BASIS,
       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
       * See the License for the specific language governing permissions and
       * limitations under the License.
       */
      pragma solidity 0.6.12;
      import { FiatTokenV1 } from "../v1/FiatTokenV1.sol";
      import { Rescuable } from "./Rescuable.sol";
      /**
       * @title FiatTokenV1_1
       * @dev ERC20 Token backed by fiat reserves
       */
      contract FiatTokenV1_1 is FiatTokenV1, Rescuable {
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * Licensed under the Apache License, Version 2.0 (the "License");
       * you may not use this file except in compliance with the License.
       * You may obtain a copy of the License at
       *
       * http://www.apache.org/licenses/LICENSE-2.0
       *
       * Unless required by applicable law or agreed to in writing, software
       * distributed under the License is distributed on an "AS IS" BASIS,
       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
       * See the License for the specific language governing permissions and
       * limitations under the License.
       */
      pragma solidity 0.6.12;
      import { ECRecover } from "./ECRecover.sol";
      import { IERC1271 } from "../interface/IERC1271.sol";
      /**
       * @dev Signature verification helper that can be used instead of `ECRecover.recover` to seamlessly support both ECDSA
       * signatures from externally owned accounts (EOAs) as well as ERC1271 signatures from smart contract wallets.
       *
       * Adapted from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/21bb89ef5bfc789b9333eb05e3ba2b7b284ac77c/contracts/utils/cryptography/SignatureChecker.sol
       */
      library SignatureChecker {
          /**
           * @dev Checks if a signature is valid for a given signer and data hash. If the signer is a smart contract, the
           * signature is validated against that smart contract using ERC1271, otherwise it's validated using `ECRecover.recover`.
           * @param signer        Address of the claimed signer
           * @param digest        Keccak-256 hash digest of the signed message
           * @param signature     Signature byte array associated with hash
           */
          function isValidSignatureNow(
              address signer,
              bytes32 digest,
              bytes memory signature
          ) external view returns (bool) {
              if (!isContract(signer)) {
                  return ECRecover.recover(digest, signature) == signer;
              }
              return isValidERC1271SignatureNow(signer, digest, signature);
          }
          /**
           * @dev Checks if a signature is valid for a given signer and data hash. The signature is validated
           * against the signer smart contract using ERC1271.
           * @param signer        Address of the claimed signer
           * @param digest        Keccak-256 hash digest of the signed message
           * @param signature     Signature byte array associated with hash
           *
           * NOTE: Unlike ECDSA signatures, contract signatures are revocable, and the outcome of this function can thus
           * change through time. It could return true at block N and false at block N+1 (or the opposite).
           */
          function isValidERC1271SignatureNow(
              address signer,
              bytes32 digest,
              bytes memory signature
          ) internal view returns (bool) {
              (bool success, bytes memory result) = signer.staticcall(
                  abi.encodeWithSelector(
                      IERC1271.isValidSignature.selector,
                      digest,
                      signature
                  )
              );
              return (success &&
                  result.length >= 32 &&
                  abi.decode(result, (bytes32)) ==
                  bytes32(IERC1271.isValidSignature.selector));
          }
          /**
           * @dev Checks if the input address is a smart contract.
           */
          function isContract(address addr) internal view returns (bool) {
              uint256 size;
              assembly {
                  size := extcodesize(addr)
              }
              return size > 0;
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * Licensed under the Apache License, Version 2.0 (the "License");
       * you may not use this file except in compliance with the License.
       * You may obtain a copy of the License at
       *
       * http://www.apache.org/licenses/LICENSE-2.0
       *
       * Unless required by applicable law or agreed to in writing, software
       * distributed under the License is distributed on an "AS IS" BASIS,
       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
       * See the License for the specific language governing permissions and
       * limitations under the License.
       */
      pragma solidity 0.6.12;
      /**
       * @dev Signature message hash utilities for producing digests to be consumed by {ECDSA} recovery or signing.
       *
       * The library provides methods for generating a hash of a message that conforms to the
       * https://eips.ethereum.org/EIPS/eip-191[EIP 191] and https://eips.ethereum.org/EIPS/eip-712[EIP 712]
       * specifications.
       */
      library MessageHashUtils {
          /**
           * @dev Returns the keccak256 digest of an EIP-712 typed data (EIP-191 version `0x01`).
           * Adapted from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/21bb89ef5bfc789b9333eb05e3ba2b7b284ac77c/contracts/utils/cryptography/MessageHashUtils.sol
           *
           * The digest is calculated from a `domainSeparator` and a `structHash`, by prefixing them with
           * `\\x19\\x01` and hashing the result. It corresponds to the hash signed by the
           * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`] JSON-RPC method as part of EIP-712.
           *
           * @param domainSeparator    Domain separator
           * @param structHash         Hashed EIP-712 data struct
           * @return digest            The keccak256 digest of an EIP-712 typed data
           */
          function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash)
              internal
              pure
              returns (bytes32 digest)
          {
              assembly {
                  let ptr := mload(0x40)
                  mstore(ptr, "\\x19\\x01")
                  mstore(add(ptr, 0x02), domainSeparator)
                  mstore(add(ptr, 0x22), structHash)
                  digest := keccak256(ptr, 0x42)
              }
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * Licensed under the Apache License, Version 2.0 (the "License");
       * you may not use this file except in compliance with the License.
       * You may obtain a copy of the License at
       *
       * http://www.apache.org/licenses/LICENSE-2.0
       *
       * Unless required by applicable law or agreed to in writing, software
       * distributed under the License is distributed on an "AS IS" BASIS,
       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
       * See the License for the specific language governing permissions and
       * limitations under the License.
       */
      pragma solidity 0.6.12;
      /**
       * @title EIP712
       * @notice A library that provides EIP712 helper functions
       */
      library EIP712 {
          /**
           * @notice Make EIP712 domain separator
           * @param name      Contract name
           * @param version   Contract version
           * @param chainId   Blockchain ID
           * @return Domain separator
           */
          function makeDomainSeparator(
              string memory name,
              string memory version,
              uint256 chainId
          ) internal view returns (bytes32) {
              return
                  keccak256(
                      abi.encode(
                          // keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)")
                          0x8b73c3c69bb8fe3d512ecc4cf759cc79239f7b179b0ffacaa9a75d522b39400f,
                          keccak256(bytes(name)),
                          keccak256(bytes(version)),
                          chainId,
                          address(this)
                      )
                  );
          }
          /**
           * @notice Make EIP712 domain separator
           * @param name      Contract name
           * @param version   Contract version
           * @return Domain separator
           */
          function makeDomainSeparator(string memory name, string memory version)
              internal
              view
              returns (bytes32)
          {
              uint256 chainId;
              assembly {
                  chainId := chainid()
              }
              return makeDomainSeparator(name, version, chainId);
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * Licensed under the Apache License, Version 2.0 (the "License");
       * you may not use this file except in compliance with the License.
       * You may obtain a copy of the License at
       *
       * http://www.apache.org/licenses/LICENSE-2.0
       *
       * Unless required by applicable law or agreed to in writing, software
       * distributed under the License is distributed on an "AS IS" BASIS,
       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
       * See the License for the specific language governing permissions and
       * limitations under the License.
       */
      pragma solidity 0.6.12;
      /**
       * @title ECRecover
       * @notice A library that provides a safe ECDSA recovery function
       */
      library ECRecover {
          /**
           * @notice Recover signer's address from a signed message
           * @dev Adapted from: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/65e4ffde586ec89af3b7e9140bdc9235d1254853/contracts/cryptography/ECDSA.sol
           * Modifications: Accept v, r, and s as separate arguments
           * @param digest    Keccak-256 hash digest of the signed message
           * @param v         v of the signature
           * @param r         r of the signature
           * @param s         s of the signature
           * @return Signer address
           */
          function recover(
              bytes32 digest,
              uint8 v,
              bytes32 r,
              bytes32 s
          ) internal pure returns (address) {
              // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
              // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
              // the valid range for s in (281): 0 < s < secp256k1n ÷ 2 + 1, and for v in (282): v ∈ {27, 28}. Most
              // signatures from current libraries generate a unique signature with an s-value in the lower half order.
              //
              // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
              // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
              // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
              // these malleable signatures as well.
              if (
                  uint256(s) >
                  0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0
              ) {
                  revert("ECRecover: invalid signature 's' value");
              }
              if (v != 27 && v != 28) {
                  revert("ECRecover: invalid signature 'v' value");
              }
              // If the signature is valid (and not malleable), return the signer address
              address signer = ecrecover(digest, v, r, s);
              require(signer != address(0), "ECRecover: invalid signature");
              return signer;
          }
          /**
           * @notice Recover signer's address from a signed message
           * @dev Adapted from: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/0053ee040a7ff1dbc39691c9e67a69f564930a88/contracts/utils/cryptography/ECDSA.sol
           * @param digest    Keccak-256 hash digest of the signed message
           * @param signature Signature byte array associated with hash
           * @return Signer address
           */
          function recover(bytes32 digest, bytes memory signature)
              internal
              pure
              returns (address)
          {
              require(signature.length == 65, "ECRecover: invalid signature length");
              bytes32 r;
              bytes32 s;
              uint8 v;
              // ecrecover takes the signature parameters, and the only way to get them
              // currently is to use assembly.
              /// @solidity memory-safe-assembly
              assembly {
                  r := mload(add(signature, 0x20))
                  s := mload(add(signature, 0x40))
                  v := byte(0, mload(add(signature, 0x60)))
              }
              return recover(digest, v, r, s);
          }
      }
      /**
       * SPDX-License-Identifier: Apache-2.0
       *
       * Copyright (c) 2023, Circle Internet Financial, LLC.
       *
       * Licensed under the Apache License, Version 2.0 (the "License");
       * you may not use this file except in compliance with the License.
       * You may obtain a copy of the License at
       *
       * http://www.apache.org/licenses/LICENSE-2.0
       *
       * Unless required by applicable law or agreed to in writing, software
       * distributed under the License is distributed on an "AS IS" BASIS,
       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
       * See the License for the specific language governing permissions and
       * limitations under the License.
       */
      pragma solidity 0.6.12;
      /**
       * @dev Interface of the ERC1271 standard signature validation method for
       * contracts as defined in https://eips.ethereum.org/EIPS/eip-1271[ERC-1271].
       */
      interface IERC1271 {
          /**
           * @dev Should return whether the signature provided is valid for the provided data
           * @param hash          Hash of the data to be signed
           * @param signature     Signature byte array associated with the provided data hash
           * @return magicValue   bytes4 magic value 0x1626ba7e when function passes
           */
          function isValidSignature(bytes32 hash, bytes memory signature)
              external
              view
              returns (bytes4 magicValue);
      }