ETH Price: $2,025.47 (-1.37%)

Transaction Decoder

Block:
19053683 at Jan-21-2024 07:15:47 AM +UTC
Transaction Fee:
0.000862257172934044 ETH $1.75
Gas Used:
89,473 Gas / 9.637065628 Gwei

Emitted Events:

239 BSGG.Transfer( from=[Sender] 0x0cfca0e82e5caa49e8be642a17998b89b0a1d922, to=[Receiver] Migration, value=133530049329850942038182 )
240 BSGG.Approval( owner=[Sender] 0x0cfca0e82e5caa49e8be642a17998b89b0a1d922, spender=[Receiver] Migration, value=0 )
241 OFTMintable.Transfer( from=0x0000000000000000000000000000000000000000, to=[Sender] 0x0cfca0e82e5caa49e8be642a17998b89b0a1d922, value=133530049329850942038182 )
242 Migration.Migrated( account=[Sender] 0x0cfca0e82e5caa49e8be642a17998b89b0a1d922, prev=133530049329850942038182, migrated=133530049329850942038182 )

Account State Difference:

  Address   Before After State Difference Code
0x0Cfca0e8...9B0A1d922
0.021157053576900293 Eth
Nonce: 60
0.020294796403966249 Eth
Nonce: 61
0.000862257172934044
0x69570f3E...e77735a25
0xdA16Cf04...9a6Bac9b3
(MEV Builder: 0xf156...8e1)
5.784648406660711944 Eth5.784657353960711944 Eth0.0000089473

Execution Trace

Migration.migrate( _amount=133530049329850942038182 )
  • BSGG.transferFrom( sender=0x0Cfca0e82E5cAa49E8BE642A17998B89B0A1d922, recipient=0x0590A8546f9242c7C175ff1782AE9340fC815dC4, amount=133530049329850942038182 ) => ( True )
  • OFTMintable.mint( _account=0x0Cfca0e82E5cAa49E8BE642A17998B89B0A1d922, _amount=133530049329850942038182 )
    File 1 of 3: Migration
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable.sol)
    pragma solidity ^0.8.0;
    import "../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.
     *
     * By default, the owner account will be the one that deploys the contract. 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;
        event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
        /**
         * @dev Initializes the contract setting the deployer as the initial owner.
         */
        constructor() {
            _transferOwnership(_msgSender());
        }
        /**
         * @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 {
            require(owner() == _msgSender(), "Ownable: caller is not the owner");
        }
        /**
         * @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 {
            require(newOwner != address(0), "Ownable: new owner is the zero address");
            _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 v4.9.0) (token/ERC20/extensions/IERC20Permit.sol)
    pragma solidity ^0.8.0;
    /**
     * @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.
     */
    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].
         */
        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 v4.9.0) (token/ERC20/IERC20.sol)
    pragma solidity ^0.8.0;
    /**
     * @dev Interface of the ERC20 standard as defined in the EIP.
     */
    interface IERC20 {
        /**
         * @dev Emitted when `value` tokens are moved from one account (`from`) to
         * another (`to`).
         *
         * Note that `value` may be zero.
         */
        event Transfer(address indexed from, address indexed to, uint256 value);
        /**
         * @dev Emitted when the allowance of a `spender` for an `owner` is set by
         * a call to {approve}. `value` is the new allowance.
         */
        event Approval(address indexed owner, address indexed spender, uint256 value);
        /**
         * @dev Returns the amount of tokens in existence.
         */
        function totalSupply() external view returns (uint256);
        /**
         * @dev Returns the amount of tokens owned by `account`.
         */
        function balanceOf(address account) external view returns (uint256);
        /**
         * @dev Moves `amount` tokens from the caller's account to `to`.
         *
         * Returns a boolean value indicating whether the operation succeeded.
         *
         * Emits a {Transfer} event.
         */
        function transfer(address to, uint256 amount) external returns (bool);
        /**
         * @dev Returns the remaining number of tokens that `spender` will be
         * allowed to spend on behalf of `owner` through {transferFrom}. This is
         * zero by default.
         *
         * This value changes when {approve} or {transferFrom} are called.
         */
        function allowance(address owner, address spender) external view returns (uint256);
        /**
         * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
         *
         * Returns a boolean value indicating whether the operation succeeded.
         *
         * IMPORTANT: Beware that changing an allowance with this method brings the risk
         * that someone may use both the old and the new allowance by unfortunate
         * transaction ordering. One possible solution to mitigate this race
         * condition is to first reduce the spender's allowance to 0 and set the
         * desired value afterwards:
         * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
         *
         * Emits an {Approval} event.
         */
        function approve(address spender, uint256 amount) external returns (bool);
        /**
         * @dev Moves `amount` tokens from `from` to `to` using the
         * allowance mechanism. `amount` is then deducted from the caller's
         * allowance.
         *
         * Returns a boolean value indicating whether the operation succeeded.
         *
         * Emits a {Transfer} event.
         */
        function transferFrom(address from, address to, uint256 amount) external returns (bool);
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.9.3) (token/ERC20/utils/SafeERC20.sol)
    pragma solidity ^0.8.0;
    import "../IERC20.sol";
    import "../extensions/IERC20Permit.sol";
    import "../../../utils/Address.sol";
    /**
     * @title SafeERC20
     * @dev Wrappers around ERC20 operations that throw on failure (when the token
     * contract returns false). Tokens that return no value (and instead revert or
     * throw on failure) are also supported, non-reverting calls are assumed to be
     * successful.
     * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
     * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
     */
    library SafeERC20 {
        using Address for address;
        /**
         * @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.encodeWithSelector(token.transfer.selector, 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.encodeWithSelector(token.transferFrom.selector, from, to, value));
        }
        /**
         * @dev Deprecated. This function has issues similar to the ones found in
         * {IERC20-approve}, and its usage is discouraged.
         *
         * Whenever possible, use {safeIncreaseAllowance} and
         * {safeDecreaseAllowance} instead.
         */
        function safeApprove(IERC20 token, address spender, uint256 value) internal {
            // safeApprove should only be called when setting an initial allowance,
            // or when resetting it to zero. To increase and decrease it, use
            // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
            require(
                (value == 0) || (token.allowance(address(this), spender) == 0),
                "SafeERC20: approve from non-zero to non-zero allowance"
            );
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
        }
        /**
         * @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);
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance + value));
        }
        /**
         * @dev Decrease the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
         * non-reverting calls are assumed to be successful.
         */
        function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
            unchecked {
                uint256 oldAllowance = token.allowance(address(this), spender);
                require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
                _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance - value));
            }
        }
        /**
         * @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.encodeWithSelector(token.approve.selector, spender, value);
            if (!_callOptionalReturnBool(token, approvalCall)) {
                _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, 0));
                _callOptionalReturn(token, approvalCall);
            }
        }
        /**
         * @dev Use a ERC-2612 signature to set the `owner` approval toward `spender` on `token`.
         * Revert on invalid signature.
         */
        function safePermit(
            IERC20Permit token,
            address owner,
            address spender,
            uint256 value,
            uint256 deadline,
            uint8 v,
            bytes32 r,
            bytes32 s
        ) internal {
            uint256 nonceBefore = token.nonces(owner);
            token.permit(owner, spender, value, deadline, v, r, s);
            uint256 nonceAfter = token.nonces(owner);
            require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
        }
        /**
         * @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");
            require(returndata.length == 0 || abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
        /**
         * @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.isContract(address(token));
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.9.0) (utils/Address.sol)
    pragma solidity ^0.8.1;
    /**
     * @dev Collection of functions related to the address type
     */
    library Address {
        /**
         * @dev Returns true if `account` is a contract.
         *
         * [IMPORTANT]
         * ====
         * It is unsafe to assume that an address for which this function returns
         * false is an externally-owned account (EOA) and not a contract.
         *
         * Among others, `isContract` will return false for the following
         * types of addresses:
         *
         *  - an externally-owned account
         *  - a contract in construction
         *  - an address where a contract will be created
         *  - an address where a contract lived, but was destroyed
         *
         * Furthermore, `isContract` will also return true if the target contract within
         * the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
         * which only has an effect at the end of a transaction.
         * ====
         *
         * [IMPORTANT]
         * ====
         * You shouldn't rely on `isContract` to protect against flash loan attacks!
         *
         * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
         * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
         * constructor.
         * ====
         */
        function isContract(address account) internal view returns (bool) {
            // This method relies on extcodesize/address.code.length, which returns 0
            // for contracts in construction, since the code is only stored at the end
            // of the constructor execution.
            return account.code.length > 0;
        }
        /**
         * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
         * `recipient`, forwarding all available gas and reverting on errors.
         *
         * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
         * of certain opcodes, possibly making contracts go over the 2300 gas limit
         * imposed by `transfer`, making them unable to receive funds via
         * `transfer`. {sendValue} removes this limitation.
         *
         * https://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/v0.8.0/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
         */
        function sendValue(address payable recipient, uint256 amount) internal {
            require(address(this).balance >= amount, "Address: insufficient balance");
            (bool success, ) = recipient.call{value: amount}("");
            require(success, "Address: unable to send value, recipient may have reverted");
        }
        /**
         * @dev Performs a Solidity function call using a low level `call`. A
         * plain `call` is an unsafe replacement for a function call: use this
         * function instead.
         *
         * If `target` reverts with a revert reason, it is bubbled up by this
         * function (like regular Solidity function calls).
         *
         * Returns the raw returned data. To convert to the expected return value,
         * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
         *
         * Requirements:
         *
         * - `target` must be a contract.
         * - calling `target` with `data` must not revert.
         *
         * _Available since v3.1._
         */
        function functionCall(address target, bytes memory data) internal returns (bytes memory) {
            return functionCallWithValue(target, data, 0, "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");
            (bool success, bytes memory returndata) = target.call{value: value}(data);
            return verifyCallResultFromTarget(target, 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) {
            (bool success, bytes memory returndata) = target.staticcall(data);
            return verifyCallResultFromTarget(target, 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) {
            (bool success, bytes memory returndata) = target.delegatecall(data);
            return verifyCallResultFromTarget(target, success, returndata, errorMessage);
        }
        /**
         * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
         * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
         *
         * _Available since v4.8._
         */
        function verifyCallResultFromTarget(
            address target,
            bool success,
            bytes memory returndata,
            string memory errorMessage
        ) internal view returns (bytes memory) {
            if (success) {
                if (returndata.length == 0) {
                    // only check isContract if the call was successful and the return data is empty
                    // otherwise we already know that it was a contract
                    require(isContract(target), "Address: call to non-contract");
                }
                return returndata;
            } else {
                _revert(returndata, errorMessage);
            }
        }
        /**
         * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
         * revert reason or using the provided one.
         *
         * _Available since v4.3._
         */
        function verifyCallResult(
            bool success,
            bytes memory returndata,
            string memory errorMessage
        ) internal pure returns (bytes memory) {
            if (success) {
                return returndata;
            } else {
                _revert(returndata, errorMessage);
            }
        }
        function _revert(bytes memory returndata, string memory errorMessage) 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(errorMessage);
            }
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
    pragma solidity ^0.8.0;
    /**
     * @dev Provides information about the current execution context, including the
     * sender of the transaction and its data. While these are generally available
     * via msg.sender and msg.data, they should not be accessed in such a direct
     * manner, since when dealing with meta-transactions the account sending and
     * paying for execution may not be the actual sender (as far as an application
     * is concerned).
     *
     * This contract is only required for intermediate, library-like contracts.
     */
    abstract contract Context {
        function _msgSender() internal view virtual returns (address) {
            return msg.sender;
        }
        function _msgData() internal view virtual returns (bytes calldata) {
            return msg.data;
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.9.0) (utils/structs/EnumerableSet.sol)
    // This file was procedurally generated from scripts/generate/templates/EnumerableSet.js.
    pragma solidity ^0.8.0;
    /**
     * @dev Library for managing
     * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
     * types.
     *
     * Sets have the following properties:
     *
     * - Elements are added, removed, and checked for existence in constant time
     * (O(1)).
     * - Elements are enumerated in O(n). No guarantees are made on the ordering.
     *
     * ```solidity
     * contract Example {
     *     // Add the library methods
     *     using EnumerableSet for EnumerableSet.AddressSet;
     *
     *     // Declare a set state variable
     *     EnumerableSet.AddressSet private mySet;
     * }
     * ```
     *
     * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
     * and `uint256` (`UintSet`) are supported.
     *
     * [WARNING]
     * ====
     * Trying to delete such a structure from storage will likely result in data corruption, rendering the structure
     * unusable.
     * See https://github.com/ethereum/solidity/pull/11843[ethereum/solidity#11843] for more info.
     *
     * In order to clean an EnumerableSet, you can either remove all elements one by one or create a fresh instance using an
     * array of EnumerableSet.
     * ====
     */
    library EnumerableSet {
        // To implement this library for multiple types with as little code
        // repetition as possible, we write it in terms of a generic Set type with
        // bytes32 values.
        // The Set implementation uses private functions, and user-facing
        // implementations (such as AddressSet) are just wrappers around the
        // underlying Set.
        // This means that we can only create new EnumerableSets for types that fit
        // in bytes32.
        struct Set {
            // Storage of set values
            bytes32[] _values;
            // Position of the value in the `values` array, plus 1 because index 0
            // means a value is not in the set.
            mapping(bytes32 => uint256) _indexes;
        }
        /**
         * @dev Add a value to a set. O(1).
         *
         * Returns true if the value was added to the set, that is if it was not
         * already present.
         */
        function _add(Set storage set, bytes32 value) private returns (bool) {
            if (!_contains(set, value)) {
                set._values.push(value);
                // The value is stored at length-1, but we add 1 to all indexes
                // and use 0 as a sentinel value
                set._indexes[value] = set._values.length;
                return true;
            } else {
                return false;
            }
        }
        /**
         * @dev Removes a value from a set. O(1).
         *
         * Returns true if the value was removed from the set, that is if it was
         * present.
         */
        function _remove(Set storage set, bytes32 value) private returns (bool) {
            // We read and store the value's index to prevent multiple reads from the same storage slot
            uint256 valueIndex = set._indexes[value];
            if (valueIndex != 0) {
                // Equivalent to contains(set, value)
                // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
                // the array, and then remove the last element (sometimes called as 'swap and pop').
                // This modifies the order of the array, as noted in {at}.
                uint256 toDeleteIndex = valueIndex - 1;
                uint256 lastIndex = set._values.length - 1;
                if (lastIndex != toDeleteIndex) {
                    bytes32 lastValue = set._values[lastIndex];
                    // Move the last value to the index where the value to delete is
                    set._values[toDeleteIndex] = lastValue;
                    // Update the index for the moved value
                    set._indexes[lastValue] = valueIndex; // Replace lastValue's index to valueIndex
                }
                // Delete the slot where the moved value was stored
                set._values.pop();
                // Delete the index for the deleted slot
                delete set._indexes[value];
                return true;
            } else {
                return false;
            }
        }
        /**
         * @dev Returns true if the value is in the set. O(1).
         */
        function _contains(Set storage set, bytes32 value) private view returns (bool) {
            return set._indexes[value] != 0;
        }
        /**
         * @dev Returns the number of values on the set. O(1).
         */
        function _length(Set storage set) private view returns (uint256) {
            return set._values.length;
        }
        /**
         * @dev Returns the value stored at position `index` in the set. O(1).
         *
         * Note that there are no guarantees on the ordering of values inside the
         * array, and it may change when more values are added or removed.
         *
         * Requirements:
         *
         * - `index` must be strictly less than {length}.
         */
        function _at(Set storage set, uint256 index) private view returns (bytes32) {
            return set._values[index];
        }
        /**
         * @dev Return the entire set in an array
         *
         * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
         * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
         * this function has an unbounded cost, and using it as part of a state-changing function may render the function
         * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
         */
        function _values(Set storage set) private view returns (bytes32[] memory) {
            return set._values;
        }
        // Bytes32Set
        struct Bytes32Set {
            Set _inner;
        }
        /**
         * @dev Add a value to a set. O(1).
         *
         * Returns true if the value was added to the set, that is if it was not
         * already present.
         */
        function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
            return _add(set._inner, value);
        }
        /**
         * @dev Removes a value from a set. O(1).
         *
         * Returns true if the value was removed from the set, that is if it was
         * present.
         */
        function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
            return _remove(set._inner, value);
        }
        /**
         * @dev Returns true if the value is in the set. O(1).
         */
        function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
            return _contains(set._inner, value);
        }
        /**
         * @dev Returns the number of values in the set. O(1).
         */
        function length(Bytes32Set storage set) internal view returns (uint256) {
            return _length(set._inner);
        }
        /**
         * @dev Returns the value stored at position `index` in the set. O(1).
         *
         * Note that there are no guarantees on the ordering of values inside the
         * array, and it may change when more values are added or removed.
         *
         * Requirements:
         *
         * - `index` must be strictly less than {length}.
         */
        function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
            return _at(set._inner, index);
        }
        /**
         * @dev Return the entire set in an array
         *
         * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
         * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
         * this function has an unbounded cost, and using it as part of a state-changing function may render the function
         * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
         */
        function values(Bytes32Set storage set) internal view returns (bytes32[] memory) {
            bytes32[] memory store = _values(set._inner);
            bytes32[] memory result;
            /// @solidity memory-safe-assembly
            assembly {
                result := store
            }
            return result;
        }
        // AddressSet
        struct AddressSet {
            Set _inner;
        }
        /**
         * @dev Add a value to a set. O(1).
         *
         * Returns true if the value was added to the set, that is if it was not
         * already present.
         */
        function add(AddressSet storage set, address value) internal returns (bool) {
            return _add(set._inner, bytes32(uint256(uint160(value))));
        }
        /**
         * @dev Removes a value from a set. O(1).
         *
         * Returns true if the value was removed from the set, that is if it was
         * present.
         */
        function remove(AddressSet storage set, address value) internal returns (bool) {
            return _remove(set._inner, bytes32(uint256(uint160(value))));
        }
        /**
         * @dev Returns true if the value is in the set. O(1).
         */
        function contains(AddressSet storage set, address value) internal view returns (bool) {
            return _contains(set._inner, bytes32(uint256(uint160(value))));
        }
        /**
         * @dev Returns the number of values in the set. O(1).
         */
        function length(AddressSet storage set) internal view returns (uint256) {
            return _length(set._inner);
        }
        /**
         * @dev Returns the value stored at position `index` in the set. O(1).
         *
         * Note that there are no guarantees on the ordering of values inside the
         * array, and it may change when more values are added or removed.
         *
         * Requirements:
         *
         * - `index` must be strictly less than {length}.
         */
        function at(AddressSet storage set, uint256 index) internal view returns (address) {
            return address(uint160(uint256(_at(set._inner, index))));
        }
        /**
         * @dev Return the entire set in an array
         *
         * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
         * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
         * this function has an unbounded cost, and using it as part of a state-changing function may render the function
         * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
         */
        function values(AddressSet storage set) internal view returns (address[] memory) {
            bytes32[] memory store = _values(set._inner);
            address[] memory result;
            /// @solidity memory-safe-assembly
            assembly {
                result := store
            }
            return result;
        }
        // UintSet
        struct UintSet {
            Set _inner;
        }
        /**
         * @dev Add a value to a set. O(1).
         *
         * Returns true if the value was added to the set, that is if it was not
         * already present.
         */
        function add(UintSet storage set, uint256 value) internal returns (bool) {
            return _add(set._inner, bytes32(value));
        }
        /**
         * @dev Removes a value from a set. O(1).
         *
         * Returns true if the value was removed from the set, that is if it was
         * present.
         */
        function remove(UintSet storage set, uint256 value) internal returns (bool) {
            return _remove(set._inner, bytes32(value));
        }
        /**
         * @dev Returns true if the value is in the set. O(1).
         */
        function contains(UintSet storage set, uint256 value) internal view returns (bool) {
            return _contains(set._inner, bytes32(value));
        }
        /**
         * @dev Returns the number of values in the set. O(1).
         */
        function length(UintSet storage set) internal view returns (uint256) {
            return _length(set._inner);
        }
        /**
         * @dev Returns the value stored at position `index` in the set. O(1).
         *
         * Note that there are no guarantees on the ordering of values inside the
         * array, and it may change when more values are added or removed.
         *
         * Requirements:
         *
         * - `index` must be strictly less than {length}.
         */
        function at(UintSet storage set, uint256 index) internal view returns (uint256) {
            return uint256(_at(set._inner, index));
        }
        /**
         * @dev Return the entire set in an array
         *
         * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
         * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
         * this function has an unbounded cost, and using it as part of a state-changing function may render the function
         * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
         */
        function values(UintSet storage set) internal view returns (uint256[] memory) {
            bytes32[] memory store = _values(set._inner);
            uint256[] memory result;
            /// @solidity memory-safe-assembly
            assembly {
                result := store
            }
            return result;
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity 0.8.20;
    interface IOFTMintable {
        /**
         * @notice Mint tokens.
         * @dev Only callable by address with minter role.
         * @param _account Address to mint tokens to.
         * @param _amount Amount of tokens to mint.
         */
        function mint(address _account, uint256 _amount) external;
        /**
         * @notice Set minter role.
         * @param _minter address for adding or removing minter role.
         * @param _isMinter boolean value for defining minter role.
         */
        function setMinter(address _minter, bool _isMinter) external;
    }
    // SPDX-License-Identifier: MIT
    pragma solidity 0.8.20;
    import "./IOFTMintable.sol";
    import "@openzeppelin/contracts/access/Ownable.sol";
    import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
    import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
    import "@openzeppelin/contracts/utils/structs/EnumerableSet.sol";
    /**
     * @title Migration
     * @notice This contract facilitates the migration of an old token to a new token.
     * @dev The exchange rate between the old and new tokens is set by the contract owner.
     * Whitelisted addresses can migrate tokens after the deadline.
     * Non-whitelisted addresses can only migrate tokens before the deadline.
     * The contract owner can add or remove addresses from the whitelist or blacklist.
     * The contract owner can also pause or unpause the migration process.
     */
    contract Migration is Ownable {
        using SafeERC20 for IERC20;
        using EnumerableSet for EnumerableSet.AddressSet;
        /// @notice Paused status of the migration.
        bool public paused;
        /// @notice Old token address to migrate from.
        IERC20 public prevToken;
        /// @notice New token address to migrate to.
        IOFTMintable public newToken;
        /// @notice Exchange rate for swapping old token to new one.
        uint256 public exchangeRate;
        /// @dev Exchange rate divider, hardcoded for the current use case.
        uint256 constant DIVIDER = 1e18;
        /// @notice Migration deadline for non-whitelisted addresses.
        uint256 public immutable deadline;
        /// @dev Set of blacklisted addresses.
        EnumerableSet.AddressSet private blacklist;
        /// @notice Amounts for whitelisted addresses.
        mapping(address => uint256) public whitelistedAmounts;
        /**
         * @notice Event emitted when the exchange rate is set.
         * @param rate exchange rate.
         */
        event SetExchangeRate(uint256 indexed rate);
        /**
         * @notice Event emitted when tokens are migrated.
         * @param account Address which migrated tokens.
         * @param prev Amount of old tokens migrated.
         * @param migrated Amount of new tokens received.
         */
        event Migrated(
            address indexed account,
            uint256 indexed prev,
            uint256 indexed migrated
        );
        /**
         * @notice Event emitted when an address is added to the blacklist.
         * @param account Address added to the blacklist.
         */
        event AddedToBlacklist(address indexed account);
        /**
         * @notice Event emitted when an address is removed from the blacklist.
         * @param account Address removed from the blacklist.
         */
        event RemovedFromBlacklist(address indexed account);
        /**
         * @notice Event emitted when an address is added to the whitelist.
         * @param account Address added to the whitelist.
         * @param amount Amount to whitelist.
         */
        event AddedWhitelistedAmount(
            address indexed account,
            uint256 indexed amount
        );
        /**
         * @notice Event emitted when address is removed from whitelist.
         * @dev White listed amount is set to 0.
         * @param account Address removed from the whitelist.
         */
        event RemovedWhitelistedAmount(address indexed account);
        /**
         * @notice Event emitted when ERC20 tokens are withdrawn by the owner.
         * @param token Address of token withdrawn.
         * @param amount Amount of token withdrawn.
         */
        event EmergencyWithdrawn(address indexed token, uint256 indexed amount);
        /**
         * @notice Event emitted when migration is paused.
         */
        event Paused();
        /**
         * @notice Event emitted when migration is unpaused.
         */
        event Unpaused();
        /**
         * @notice Modifier to check if the caller is in the blacklist.
         */
        modifier isBlacklist() {
            require(
                !blacklist.contains(msg.sender),
                "Address is listed in blacklist"
            );
            _;
        }
        /**
         * @dev Constructor.
         * @param _prev address of previous token.
         * @param _migrated address of new token.
         * @param _rate exchange rate.
         * @param _deadline migration deadline (timestamp).
         */
        constructor(
            address _prev,
            address _migrated,
            uint256 _rate,
            uint256 _deadline
        ) {
            require(_prev != address(0), "Invalid address");
            require(_migrated != address(0), "Invalid address");
            require(_rate != 0, "Invalid exchange rate");
            require(_deadline >= block.timestamp + 7 days, "Invalid deadline");
            prevToken = IERC20(_prev);
            newToken = IOFTMintable(_migrated);
            exchangeRate = _rate;
            deadline = _deadline;
            emit SetExchangeRate(_rate);
        }
        ///////////////////////
        /// User Functions  ///
        ///////////////////////
        /**
         * @notice Migrate old tokens to new tokens.
         * @dev This function can only be called by non-blacklisted addresses.
         * @dev Account needs first to approve the contract to spend the old tokens.
         * @dev If the deadline is passed, the account needs to have whitelisted amount.
         * @param _amount amount of old tokens to migrate.
         */
        function migrate(uint256 _amount) external isBlacklist {
            require(
                block.timestamp <= deadline ||
                    whitelistedAmounts[msg.sender] >= _amount,
                "Deadline; whitelisted < _amount"
            );
            require(_amount != 0, "Invalid migration amount");
            require(!paused, "Migration paused");
            // 1. receive previous token
            prevToken.safeTransferFrom(msg.sender, address(this), _amount);
            // 2. migrate to new token
            uint256 migratedAmt = (_amount * exchangeRate) / DIVIDER;
            require(migratedAmt != 0, "Invalid migrated amount");
            if (block.timestamp > deadline) {
                whitelistedAmounts[msg.sender] -= _amount;
            }
            newToken.mint(msg.sender, migratedAmt);
            emit Migrated(msg.sender, _amount, migratedAmt);
        }
        ///////////////////////
        /// Owner Functions ///
        ///////////////////////
        /**
         * @notice Set exchange rate.
         * @dev This function can only be called by the contract owner.
         * @param _rate new exchange rate.
         */
        function setExchangeRate(uint256 _rate) external onlyOwner {
            require(_rate != 0, "Invalid exchange rate");
            exchangeRate = _rate;
            emit SetExchangeRate(_rate);
        }
        /**
         * @notice Add whitelisted amounts for the accounts.
         * @dev This function can only be called by the contract owner.
         * @dev Both `_list` and `_amounts` arrays must have the same length.
         * @param _list array of accounts.
         * @param _amounts array of amounts to whitelist.
         */
        function addWhitelistedAmounts(
            address[] calldata _list,
            uint256[] calldata _amounts
        ) external onlyOwner {
            require(_list.length != 0, "Invalid array length");
            require(_list.length == _amounts.length, "Array length mismatch");
            for (uint i; i < _list.length; ) {
                whitelistedAmounts[_list[i]] += _amounts[i];
                emit AddedWhitelistedAmount(_list[i], _amounts[i]);
                unchecked {
                    ++i;
                }
            }
        }
        /**
         * @notice Remove whitelisted amount of the account.
         * @dev This function can only be called by the contract owner.
         * @param _list array of accounts.
         */
        function removeWhitelistedAmounts(
            address[] memory _list
        ) external onlyOwner {
            require(_list.length != 0, "Invalid array length");
            for (uint i; i < _list.length; ) {
                whitelistedAmounts[_list[i]] = 0;
                emit RemovedWhitelistedAmount(_list[i]);
                unchecked {
                    ++i;
                }
            }
        }
        /**
         * @notice Add addresses to blacklist.
         * @dev This function can only be called by the contract owner.
         * @param _list array of blacklisted accounts.
         */
        function addBlacklist(address[] memory _list) external onlyOwner {
            require(_list.length != 0, "Invalid array length");
            for (uint i; i < _list.length; ) {
                if (!blacklist.contains(_list[i])) {
                    blacklist.add(_list[i]);
                    emit AddedToBlacklist(_list[i]);
                }
                unchecked {
                    ++i;
                }
            }
        }
        /**
         * @notice Remove addresses from blacklist.
         * @dev This function can only be called by the contract owner.
         * @param _list array of accounts.
         */
        function removeBlacklist(address[] memory _list) external onlyOwner {
            require(_list.length != 0, "Invalid array length");
            for (uint i; i < _list.length; ) {
                if (blacklist.contains(_list[i])) {
                    blacklist.remove(_list[i]);
                    emit RemovedFromBlacklist(_list[i]);
                }
                unchecked {
                    ++i;
                }
            }
        }
        /**
         * @notice Emergency withdraw ERC20 tokens.
         * @dev This function can only be called by the contract owner.
         * @param _token address of ERC20 token to withdraw.
         */
        function emergencyWithdraw(IERC20 _token) external onlyOwner {
            require(address(_token) != address(prevToken), "Invalid address");
            uint256 _amount = _token.balanceOf(address(this));
            _token.safeTransfer(owner(), _amount);
            emit EmergencyWithdrawn(address(_token), _amount);
        }
        /**
         * @notice Pause migration.
         * @dev This function can only be called by the contract owner.
         */
        function pause() external onlyOwner {
            paused = true;
            emit Paused();
        }
        /**
         * @notice Unpause migration.
         * @dev This function can only be called by the contract owner.
         */
        function unpause() external onlyOwner {
            paused = false;
            emit Unpaused();
        }
    }
    

    File 2 of 3: BSGG
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    import {ERC20, ERC20Permit} from "@openzeppelin/contracts/token/ERC20/extensions/draft-ERC20Permit.sol";
    import "@openzeppelin/contracts/access/Ownable.sol";
    contract BSGG is ERC20Permit, Ownable {
        constructor() ERC20("Betswap.gg", "BSGG") ERC20Permit("Betswap.gg") {
            _mint(msg.sender, 10000000000000000000000000000);
        }
        function decimals() public pure override returns (uint8) {
            return 18;
        }
        function burn(uint256 amount) onlyOwner public returns (bool) {
            _burn(msg.sender, amount);
            return true;
        }
    }// SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.0 (utils/cryptography/draft-EIP712.sol)
    pragma solidity ^0.8.0;
    import "./ECDSA.sol";
    /**
     * @dev https://eips.ethereum.org/EIPS/eip-712[EIP 712] is a standard for hashing and signing of typed structured data.
     *
     * The encoding specified in the EIP is very generic, and such a generic implementation in Solidity is not feasible,
     * thus this contract does not implement the encoding itself. Protocols need to implement the type-specific encoding
     * they need in their contracts using a combination of `abi.encode` and `keccak256`.
     *
     * This contract implements the EIP 712 domain separator ({_domainSeparatorV4}) that is used as part of the encoding
     * scheme, and the final step of the encoding to obtain the message digest that is then signed via ECDSA
     * ({_hashTypedDataV4}).
     *
     * The implementation of the domain separator was designed to be as efficient as possible while still properly updating
     * the chain id to protect against replay attacks on an eventual fork of the chain.
     *
     * NOTE: This contract implements the version of the encoding known as "v4", as implemented by the JSON RPC method
     * https://docs.metamask.io/guide/signing-data.html[`eth_signTypedDataV4` in MetaMask].
     *
     * _Available since v3.4._
     */
    abstract contract EIP712 {
        /* solhint-disable var-name-mixedcase */
        // Cache the domain separator as an immutable value, but also store the chain id that it corresponds to, in order to
        // invalidate the cached domain separator if the chain id changes.
        bytes32 private immutable _CACHED_DOMAIN_SEPARATOR;
        uint256 private immutable _CACHED_CHAIN_ID;
        address private immutable _CACHED_THIS;
        bytes32 private immutable _HASHED_NAME;
        bytes32 private immutable _HASHED_VERSION;
        bytes32 private immutable _TYPE_HASH;
        /* solhint-enable var-name-mixedcase */
        /**
         * @dev Initializes the domain separator and parameter caches.
         *
         * The meaning of `name` and `version` is specified in
         * https://eips.ethereum.org/EIPS/eip-712#definition-of-domainseparator[EIP 712]:
         *
         * - `name`: the user readable name of the signing domain, i.e. the name of the DApp or the protocol.
         * - `version`: the current major version of the signing domain.
         *
         * NOTE: These parameters cannot be changed except through a xref:learn::upgrading-smart-contracts.adoc[smart
         * contract upgrade].
         */
        constructor(string memory name, string memory version) {
            bytes32 hashedName = keccak256(bytes(name));
            bytes32 hashedVersion = keccak256(bytes(version));
            bytes32 typeHash = keccak256(
                "EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"
            );
            _HASHED_NAME = hashedName;
            _HASHED_VERSION = hashedVersion;
            _CACHED_CHAIN_ID = block.chainid;
            _CACHED_DOMAIN_SEPARATOR = _buildDomainSeparator(typeHash, hashedName, hashedVersion);
            _CACHED_THIS = address(this);
            _TYPE_HASH = typeHash;
        }
        /**
         * @dev Returns the domain separator for the current chain.
         */
        function _domainSeparatorV4() internal view returns (bytes32) {
            if (address(this) == _CACHED_THIS && block.chainid == _CACHED_CHAIN_ID) {
                return _CACHED_DOMAIN_SEPARATOR;
            } else {
                return _buildDomainSeparator(_TYPE_HASH, _HASHED_NAME, _HASHED_VERSION);
            }
        }
        function _buildDomainSeparator(
            bytes32 typeHash,
            bytes32 nameHash,
            bytes32 versionHash
        ) private view returns (bytes32) {
            return keccak256(abi.encode(typeHash, nameHash, versionHash, block.chainid, address(this)));
        }
        /**
         * @dev Given an already https://eips.ethereum.org/EIPS/eip-712#definition-of-hashstruct[hashed struct], this
         * function returns the hash of the fully encoded EIP712 message for this domain.
         *
         * This hash can be used together with {ECDSA-recover} to obtain the signer of a message. For example:
         *
         * ```solidity
         * bytes32 digest = _hashTypedDataV4(keccak256(abi.encode(
         *     keccak256("Mail(address to,string contents)"),
         *     mailTo,
         *     keccak256(bytes(mailContents))
         * )));
         * address signer = ECDSA.recover(digest, signature);
         * ```
         */
        function _hashTypedDataV4(bytes32 structHash) internal view virtual returns (bytes32) {
            return ECDSA.toTypedDataHash(_domainSeparatorV4(), structHash);
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.0 (utils/cryptography/ECDSA.sol)
    pragma solidity ^0.8.0;
    import "../Strings.sol";
    /**
     * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
     *
     * These functions can be used to verify that a message was signed by the holder
     * of the private keys of a given address.
     */
    library ECDSA {
        enum RecoverError {
            NoError,
            InvalidSignature,
            InvalidSignatureLength,
            InvalidSignatureS,
            InvalidSignatureV
        }
        function _throwError(RecoverError error) private pure {
            if (error == RecoverError.NoError) {
                return; // no error: do nothing
            } else if (error == RecoverError.InvalidSignature) {
                revert("ECDSA: invalid signature");
            } else if (error == RecoverError.InvalidSignatureLength) {
                revert("ECDSA: invalid signature length");
            } else if (error == RecoverError.InvalidSignatureS) {
                revert("ECDSA: invalid signature 's' value");
            } else if (error == RecoverError.InvalidSignatureV) {
                revert("ECDSA: invalid signature 'v' value");
            }
        }
        /**
         * @dev Returns the address that signed a hashed message (`hash`) with
         * `signature` or error string. This address can then be used for verification purposes.
         *
         * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
         * this function rejects them by requiring the `s` value to be in the lower
         * half order, and the `v` value to be either 27 or 28.
         *
         * IMPORTANT: `hash` _must_ be the result of a hash operation for the
         * verification to be secure: it is possible to craft signatures that
         * recover to arbitrary addresses for non-hashed data. A safe way to ensure
         * this is by receiving a hash of the original message (which may otherwise
         * be too long), and then calling {toEthSignedMessageHash} on it.
         *
         * Documentation for signature generation:
         * - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
         * - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
         *
         * _Available since v4.3._
         */
        function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) {
            // Check the signature length
            // - case 65: r,s,v signature (standard)
            // - case 64: r,vs signature (cf https://eips.ethereum.org/EIPS/eip-2098) _Available since v4.1._
            if (signature.length == 65) {
                bytes32 r;
                bytes32 s;
                uint8 v;
                // ecrecover takes the signature parameters, and the only way to get them
                // currently is to use assembly.
                assembly {
                    r := mload(add(signature, 0x20))
                    s := mload(add(signature, 0x40))
                    v := byte(0, mload(add(signature, 0x60)))
                }
                return tryRecover(hash, v, r, s);
            } else if (signature.length == 64) {
                bytes32 r;
                bytes32 vs;
                // ecrecover takes the signature parameters, and the only way to get them
                // currently is to use assembly.
                assembly {
                    r := mload(add(signature, 0x20))
                    vs := mload(add(signature, 0x40))
                }
                return tryRecover(hash, r, vs);
            } else {
                return (address(0), RecoverError.InvalidSignatureLength);
            }
        }
        /**
         * @dev Returns the address that signed a hashed message (`hash`) with
         * `signature`. This address can then be used for verification purposes.
         *
         * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
         * this function rejects them by requiring the `s` value to be in the lower
         * half order, and the `v` value to be either 27 or 28.
         *
         * IMPORTANT: `hash` _must_ be the result of a hash operation for the
         * verification to be secure: it is possible to craft signatures that
         * recover to arbitrary addresses for non-hashed data. A safe way to ensure
         * this is by receiving a hash of the original message (which may otherwise
         * be too long), and then calling {toEthSignedMessageHash} on it.
         */
        function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
            (address recovered, RecoverError error) = tryRecover(hash, signature);
            _throwError(error);
            return recovered;
        }
        /**
         * @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
         *
         * See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
         *
         * _Available since v4.3._
         */
        function tryRecover(
            bytes32 hash,
            bytes32 r,
            bytes32 vs
        ) internal pure returns (address, RecoverError) {
            bytes32 s;
            uint8 v;
            assembly {
                s := and(vs, 0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff)
                v := add(shr(255, vs), 27)
            }
            return tryRecover(hash, v, r, s);
        }
        /**
         * @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
         *
         * _Available since v4.2._
         */
        function recover(
            bytes32 hash,
            bytes32 r,
            bytes32 vs
        ) internal pure returns (address) {
            (address recovered, RecoverError error) = tryRecover(hash, r, vs);
            _throwError(error);
            return recovered;
        }
        /**
         * @dev Overload of {ECDSA-tryRecover} that receives the `v`,
         * `r` and `s` signature fields separately.
         *
         * _Available since v4.3._
         */
        function tryRecover(
            bytes32 hash,
            uint8 v,
            bytes32 r,
            bytes32 s
        ) internal pure returns (address, RecoverError) {
            // 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 (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): 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) {
                return (address(0), RecoverError.InvalidSignatureS);
            }
            if (v != 27 && v != 28) {
                return (address(0), RecoverError.InvalidSignatureV);
            }
            // If the signature is valid (and not malleable), return the signer address
            address signer = ecrecover(hash, v, r, s);
            if (signer == address(0)) {
                return (address(0), RecoverError.InvalidSignature);
            }
            return (signer, RecoverError.NoError);
        }
        /**
         * @dev Overload of {ECDSA-recover} that receives the `v`,
         * `r` and `s` signature fields separately.
         */
        function recover(
            bytes32 hash,
            uint8 v,
            bytes32 r,
            bytes32 s
        ) internal pure returns (address) {
            (address recovered, RecoverError error) = tryRecover(hash, v, r, s);
            _throwError(error);
            return recovered;
        }
        /**
         * @dev Returns an Ethereum Signed Message, created from a `hash`. This
         * produces hash corresponding to the one signed with the
         * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
         * JSON-RPC method as part of EIP-191.
         *
         * See {recover}.
         */
        function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) {
            // 32 is the length in bytes of hash,
            // enforced by the type signature above
            return keccak256(abi.encodePacked("\\x19Ethereum Signed Message:\
    32", hash));
        }
        /**
         * @dev Returns an Ethereum Signed Message, created from `s`. This
         * produces hash corresponding to the one signed with the
         * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
         * JSON-RPC method as part of EIP-191.
         *
         * See {recover}.
         */
        function toEthSignedMessageHash(bytes memory s) internal pure returns (bytes32) {
            return keccak256(abi.encodePacked("\\x19Ethereum Signed Message:\
    ", Strings.toString(s.length), s));
        }
        /**
         * @dev Returns an Ethereum Signed Typed Data, created from a
         * `domainSeparator` and a `structHash`. This produces hash corresponding
         * to the one signed with the
         * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]
         * JSON-RPC method as part of EIP-712.
         *
         * See {recover}.
         */
        function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32) {
            return keccak256(abi.encodePacked("\\x19\\x01", domainSeparator, structHash));
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.0 (utils/Strings.sol)
    pragma solidity ^0.8.0;
    /**
     * @dev String operations.
     */
    library Strings {
        bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
        /**
         * @dev Converts a `uint256` to its ASCII `string` decimal representation.
         */
        function toString(uint256 value) internal pure returns (string memory) {
            // Inspired by OraclizeAPI's implementation - MIT licence
            // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
            if (value == 0) {
                return "0";
            }
            uint256 temp = value;
            uint256 digits;
            while (temp != 0) {
                digits++;
                temp /= 10;
            }
            bytes memory buffer = new bytes(digits);
            while (value != 0) {
                digits -= 1;
                buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
                value /= 10;
            }
            return string(buffer);
        }
        /**
         * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
         */
        function toHexString(uint256 value) internal pure returns (string memory) {
            if (value == 0) {
                return "0x00";
            }
            uint256 temp = value;
            uint256 length = 0;
            while (temp != 0) {
                length++;
                temp >>= 8;
            }
            return toHexString(value, length);
        }
        /**
         * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
         */
        function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
            bytes memory buffer = new bytes(2 * length + 2);
            buffer[0] = "0";
            buffer[1] = "x";
            for (uint256 i = 2 * length + 1; i > 1; --i) {
                buffer[i] = _HEX_SYMBOLS[value & 0xf];
                value >>= 4;
            }
            require(value == 0, "Strings: hex length insufficient");
            return string(buffer);
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.0 (utils/Counters.sol)
    pragma solidity ^0.8.0;
    /**
     * @title Counters
     * @author Matt Condon (@shrugs)
     * @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number
     * of elements in a mapping, issuing ERC721 ids, or counting request ids.
     *
     * Include with `using Counters for Counters.Counter;`
     */
    library Counters {
        struct Counter {
            // This variable should never be directly accessed by users of the library: interactions must be restricted to
            // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
            // this feature: see https://github.com/ethereum/solidity/issues/4637
            uint256 _value; // default: 0
        }
        function current(Counter storage counter) internal view returns (uint256) {
            return counter._value;
        }
        function increment(Counter storage counter) internal {
            unchecked {
                counter._value += 1;
            }
        }
        function decrement(Counter storage counter) internal {
            uint256 value = counter._value;
            require(value > 0, "Counter: decrement overflow");
            unchecked {
                counter._value = value - 1;
            }
        }
        function reset(Counter storage counter) internal {
            counter._value = 0;
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.0 (utils/Context.sol)
    pragma solidity ^0.8.0;
    /**
     * @dev Provides information about the current execution context, including the
     * sender of the transaction and its data. While these are generally available
     * via msg.sender and msg.data, they should not be accessed in such a direct
     * manner, since when dealing with meta-transactions the account sending and
     * paying for execution may not be the actual sender (as far as an application
     * is concerned).
     *
     * This contract is only required for intermediate, library-like contracts.
     */
    abstract contract Context {
        function _msgSender() internal view virtual returns (address) {
            return msg.sender;
        }
        function _msgData() internal view virtual returns (bytes calldata) {
            return msg.data;
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.0 (token/ERC20/extensions/draft-IERC20Permit.sol)
    pragma solidity ^0.8.0;
    /**
     * @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.
     */
    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].
         */
        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 v4.4.0 (token/ERC20/extensions/draft-ERC20Permit.sol)
    pragma solidity ^0.8.0;
    import "./draft-IERC20Permit.sol";
    import "../ERC20.sol";
    import "../../../utils/cryptography/draft-EIP712.sol";
    import "../../../utils/cryptography/ECDSA.sol";
    import "../../../utils/Counters.sol";
    /**
     * @dev Implementation 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.
     *
     * _Available since v3.4._
     */
    abstract contract ERC20Permit is ERC20, IERC20Permit, EIP712 {
        using Counters for Counters.Counter;
        mapping(address => Counters.Counter) private _nonces;
        // solhint-disable-next-line var-name-mixedcase
        bytes32 private immutable _PERMIT_TYPEHASH =
            keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
        /**
         * @dev Initializes the {EIP712} domain separator using the `name` parameter, and setting `version` to `"1"`.
         *
         * It's a good idea to use the same `name` that is defined as the ERC20 token name.
         */
        constructor(string memory name) EIP712(name, "1") {}
        /**
         * @dev See {IERC20Permit-permit}.
         */
        function permit(
            address owner,
            address spender,
            uint256 value,
            uint256 deadline,
            uint8 v,
            bytes32 r,
            bytes32 s
        ) public virtual override {
            require(block.timestamp <= deadline, "ERC20Permit: expired deadline");
            bytes32 structHash = keccak256(abi.encode(_PERMIT_TYPEHASH, owner, spender, value, _useNonce(owner), deadline));
            bytes32 hash = _hashTypedDataV4(structHash);
            address signer = ECDSA.recover(hash, v, r, s);
            require(signer == owner, "ERC20Permit: invalid signature");
            _approve(owner, spender, value);
        }
        /**
         * @dev See {IERC20Permit-nonces}.
         */
        function nonces(address owner) public view virtual override returns (uint256) {
            return _nonces[owner].current();
        }
        /**
         * @dev See {IERC20Permit-DOMAIN_SEPARATOR}.
         */
        // solhint-disable-next-line func-name-mixedcase
        function DOMAIN_SEPARATOR() external view override returns (bytes32) {
            return _domainSeparatorV4();
        }
        /**
         * @dev "Consume a nonce": return the current value and increment.
         *
         * _Available since v4.1._
         */
        function _useNonce(address owner) internal virtual returns (uint256 current) {
            Counters.Counter storage nonce = _nonces[owner];
            current = nonce.current();
            nonce.increment();
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.0 (token/ERC20/extensions/IERC20Metadata.sol)
    pragma solidity ^0.8.0;
    import "../IERC20.sol";
    /**
     * @dev Interface for the optional metadata functions from the ERC20 standard.
     *
     * _Available since v4.1._
     */
    interface IERC20Metadata is IERC20 {
        /**
         * @dev Returns the name of the token.
         */
        function name() external view returns (string memory);
        /**
         * @dev Returns the symbol of the token.
         */
        function symbol() external view returns (string memory);
        /**
         * @dev Returns the decimals places of the token.
         */
        function decimals() external view returns (uint8);
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.0 (token/ERC20/IERC20.sol)
    pragma solidity ^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
    // OpenZeppelin Contracts v4.4.0 (token/ERC20/ERC20.sol)
    pragma solidity ^0.8.0;
    import "./IERC20.sol";
    import "./extensions/IERC20Metadata.sol";
    import "../../utils/Context.sol";
    /**
     * @dev Implementation of the {IERC20} interface.
     *
     * This implementation is agnostic to the way tokens are created. This means
     * that a supply mechanism has to be added in a derived contract using {_mint}.
     * For a generic mechanism see {ERC20PresetMinterPauser}.
     *
     * TIP: For a detailed writeup see our guide
     * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
     * to implement supply mechanisms].
     *
     * We have followed general OpenZeppelin Contracts guidelines: functions revert
     * instead returning `false` on failure. This behavior is nonetheless
     * conventional and does not conflict with the expectations of ERC20
     * applications.
     *
     * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
     * This allows applications to reconstruct the allowance for all accounts just
     * by listening to said events. Other implementations of the EIP may not emit
     * these events, as it isn't required by the specification.
     *
     * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
     * functions have been added to mitigate the well-known issues around setting
     * allowances. See {IERC20-approve}.
     */
    contract ERC20 is Context, IERC20, IERC20Metadata {
        mapping(address => uint256) private _balances;
        mapping(address => mapping(address => uint256)) private _allowances;
        uint256 private _totalSupply;
        string private _name;
        string private _symbol;
        /**
         * @dev Sets the values for {name} and {symbol}.
         *
         * The default value of {decimals} is 18. To select a different value for
         * {decimals} you should overload it.
         *
         * All two of these values are immutable: they can only be set once during
         * construction.
         */
        constructor(string memory name_, string memory symbol_) {
            _name = name_;
            _symbol = symbol_;
        }
        /**
         * @dev Returns the name of the token.
         */
        function name() public view virtual override returns (string memory) {
            return _name;
        }
        /**
         * @dev Returns the symbol of the token, usually a shorter version of the
         * name.
         */
        function symbol() public view virtual override returns (string memory) {
            return _symbol;
        }
        /**
         * @dev Returns the number of decimals used to get its user representation.
         * For example, if `decimals` equals `2`, a balance of `505` tokens should
         * be displayed to a user as `5.05` (`505 / 10 ** 2`).
         *
         * Tokens usually opt for a value of 18, imitating the relationship between
         * Ether and Wei. This is the value {ERC20} uses, unless this function is
         * overridden;
         *
         * NOTE: This information is only used for _display_ purposes: it in
         * no way affects any of the arithmetic of the contract, including
         * {IERC20-balanceOf} and {IERC20-transfer}.
         */
        function decimals() public view virtual override returns (uint8) {
            return 18;
        }
        /**
         * @dev See {IERC20-totalSupply}.
         */
        function totalSupply() public view virtual override returns (uint256) {
            return _totalSupply;
        }
        /**
         * @dev See {IERC20-balanceOf}.
         */
        function balanceOf(address account) public view virtual override returns (uint256) {
            return _balances[account];
        }
        /**
         * @dev See {IERC20-transfer}.
         *
         * Requirements:
         *
         * - `recipient` cannot be the zero address.
         * - the caller must have a balance of at least `amount`.
         */
        function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
            _transfer(_msgSender(), recipient, amount);
            return true;
        }
        /**
         * @dev See {IERC20-allowance}.
         */
        function allowance(address owner, address spender) public view virtual override returns (uint256) {
            return _allowances[owner][spender];
        }
        /**
         * @dev See {IERC20-approve}.
         *
         * Requirements:
         *
         * - `spender` cannot be the zero address.
         */
        function approve(address spender, uint256 amount) public virtual override returns (bool) {
            _approve(_msgSender(), spender, amount);
            return true;
        }
        /**
         * @dev See {IERC20-transferFrom}.
         *
         * Emits an {Approval} event indicating the updated allowance. This is not
         * required by the EIP. See the note at the beginning of {ERC20}.
         *
         * Requirements:
         *
         * - `sender` and `recipient` cannot be the zero address.
         * - `sender` must have a balance of at least `amount`.
         * - the caller must have allowance for ``sender``'s tokens of at least
         * `amount`.
         */
        function transferFrom(
            address sender,
            address recipient,
            uint256 amount
        ) public virtual override returns (bool) {
            _transfer(sender, recipient, amount);
            uint256 currentAllowance = _allowances[sender][_msgSender()];
            require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
            unchecked {
                _approve(sender, _msgSender(), currentAllowance - amount);
            }
            return true;
        }
        /**
         * @dev Atomically increases the allowance granted to `spender` by the caller.
         *
         * This is an alternative to {approve} that can be used as a mitigation for
         * problems described in {IERC20-approve}.
         *
         * Emits an {Approval} event indicating the updated allowance.
         *
         * Requirements:
         *
         * - `spender` cannot be the zero address.
         */
        function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
            _approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
            return true;
        }
        /**
         * @dev Atomically decreases the allowance granted to `spender` by the caller.
         *
         * This is an alternative to {approve} that can be used as a mitigation for
         * problems described in {IERC20-approve}.
         *
         * Emits an {Approval} event indicating the updated allowance.
         *
         * Requirements:
         *
         * - `spender` cannot be the zero address.
         * - `spender` must have allowance for the caller of at least
         * `subtractedValue`.
         */
        function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
            uint256 currentAllowance = _allowances[_msgSender()][spender];
            require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
            unchecked {
                _approve(_msgSender(), spender, currentAllowance - subtractedValue);
            }
            return true;
        }
        /**
         * @dev Moves `amount` of tokens from `sender` to `recipient`.
         *
         * This internal function is equivalent to {transfer}, and can be used to
         * e.g. implement automatic token fees, slashing mechanisms, etc.
         *
         * Emits a {Transfer} event.
         *
         * Requirements:
         *
         * - `sender` cannot be the zero address.
         * - `recipient` cannot be the zero address.
         * - `sender` must have a balance of at least `amount`.
         */
        function _transfer(
            address sender,
            address recipient,
            uint256 amount
        ) internal virtual {
            require(sender != address(0), "ERC20: transfer from the zero address");
            require(recipient != address(0), "ERC20: transfer to the zero address");
            _beforeTokenTransfer(sender, recipient, amount);
            uint256 senderBalance = _balances[sender];
            require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
            unchecked {
                _balances[sender] = senderBalance - amount;
            }
            _balances[recipient] += amount;
            emit Transfer(sender, recipient, amount);
            _afterTokenTransfer(sender, recipient, amount);
        }
        /** @dev Creates `amount` tokens and assigns them to `account`, increasing
         * the total supply.
         *
         * Emits a {Transfer} event with `from` set to the zero address.
         *
         * Requirements:
         *
         * - `account` cannot be the zero address.
         */
        function _mint(address account, uint256 amount) internal virtual {
            require(account != address(0), "ERC20: mint to the zero address");
            _beforeTokenTransfer(address(0), account, amount);
            _totalSupply += amount;
            _balances[account] += amount;
            emit Transfer(address(0), account, amount);
            _afterTokenTransfer(address(0), account, amount);
        }
        /**
         * @dev Destroys `amount` tokens from `account`, reducing the
         * total supply.
         *
         * Emits a {Transfer} event with `to` set to the zero address.
         *
         * Requirements:
         *
         * - `account` cannot be the zero address.
         * - `account` must have at least `amount` tokens.
         */
        function _burn(address account, uint256 amount) internal virtual {
            require(account != address(0), "ERC20: burn from the zero address");
            _beforeTokenTransfer(account, address(0), amount);
            uint256 accountBalance = _balances[account];
            require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
            unchecked {
                _balances[account] = accountBalance - amount;
            }
            _totalSupply -= amount;
            emit Transfer(account, address(0), amount);
            _afterTokenTransfer(account, address(0), amount);
        }
        /**
         * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
         *
         * This internal function is equivalent to `approve`, and can be used to
         * e.g. set automatic allowances for certain subsystems, etc.
         *
         * Emits an {Approval} event.
         *
         * Requirements:
         *
         * - `owner` cannot be the zero address.
         * - `spender` cannot be the zero address.
         */
        function _approve(
            address owner,
            address spender,
            uint256 amount
        ) internal virtual {
            require(owner != address(0), "ERC20: approve from the zero address");
            require(spender != address(0), "ERC20: approve to the zero address");
            _allowances[owner][spender] = amount;
            emit Approval(owner, spender, amount);
        }
        /**
         * @dev Hook that is called before any transfer of tokens. This includes
         * minting and burning.
         *
         * Calling conditions:
         *
         * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
         * will be transferred to `to`.
         * - when `from` is zero, `amount` tokens will be minted for `to`.
         * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
         * - `from` and `to` are never both zero.
         *
         * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
         */
        function _beforeTokenTransfer(
            address from,
            address to,
            uint256 amount
        ) internal virtual {}
        /**
         * @dev Hook that is called after any transfer of tokens. This includes
         * minting and burning.
         *
         * Calling conditions:
         *
         * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
         * has been transferred to `to`.
         * - when `from` is zero, `amount` tokens have been minted for `to`.
         * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
         * - `from` and `to` are never both zero.
         *
         * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
         */
        function _afterTokenTransfer(
            address from,
            address to,
            uint256 amount
        ) internal virtual {}
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.0 (access/Ownable.sol)
    pragma solidity ^0.8.0;
    import "../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.
     *
     * By default, the owner account will be the one that deploys the contract. 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;
        event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
        /**
         * @dev Initializes the contract setting the deployer as the initial owner.
         */
        constructor() {
            _transferOwnership(_msgSender());
        }
        /**
         * @dev Returns the address of the current owner.
         */
        function owner() public view virtual returns (address) {
            return _owner;
        }
        /**
         * @dev Throws if called by any account other than the owner.
         */
        modifier onlyOwner() {
            require(owner() == _msgSender(), "Ownable: caller is not the owner");
            _;
        }
        /**
         * @dev Leaves the contract without owner. It will not be possible to call
         * `onlyOwner` functions anymore. Can only be called by the current owner.
         *
         * NOTE: Renouncing ownership will leave the contract without an owner,
         * thereby removing 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 {
            require(newOwner != address(0), "Ownable: new owner is the zero address");
            _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);
        }
    }
    

    File 3 of 3: OFTMintable
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable.sol)
    pragma solidity ^0.8.0;
    import "../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.
     *
     * By default, the owner account will be the one that deploys the contract. 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;
        event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
        /**
         * @dev Initializes the contract setting the deployer as the initial owner.
         */
        constructor() {
            _transferOwnership(_msgSender());
        }
        /**
         * @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 {
            require(owner() == _msgSender(), "Ownable: caller is not the owner");
        }
        /**
         * @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 {
            require(newOwner != address(0), "Ownable: new owner is the zero address");
            _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 v4.9.0) (token/ERC20/ERC20.sol)
    pragma solidity ^0.8.0;
    import "./IERC20.sol";
    import "./extensions/IERC20Metadata.sol";
    import "../../utils/Context.sol";
    /**
     * @dev Implementation of the {IERC20} interface.
     *
     * This implementation is agnostic to the way tokens are created. This means
     * that a supply mechanism has to be added in a derived contract using {_mint}.
     * For a generic mechanism see {ERC20PresetMinterPauser}.
     *
     * TIP: For a detailed writeup see our guide
     * https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
     * to implement supply mechanisms].
     *
     * The default value of {decimals} is 18. To change this, you should override
     * this function so it returns a different value.
     *
     * We have followed general OpenZeppelin Contracts guidelines: functions revert
     * instead returning `false` on failure. This behavior is nonetheless
     * conventional and does not conflict with the expectations of ERC20
     * applications.
     *
     * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
     * This allows applications to reconstruct the allowance for all accounts just
     * by listening to said events. Other implementations of the EIP may not emit
     * these events, as it isn't required by the specification.
     *
     * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
     * functions have been added to mitigate the well-known issues around setting
     * allowances. See {IERC20-approve}.
     */
    contract ERC20 is Context, IERC20, IERC20Metadata {
        mapping(address => uint256) private _balances;
        mapping(address => mapping(address => uint256)) private _allowances;
        uint256 private _totalSupply;
        string private _name;
        string private _symbol;
        /**
         * @dev Sets the values for {name} and {symbol}.
         *
         * All two of these values are immutable: they can only be set once during
         * construction.
         */
        constructor(string memory name_, string memory symbol_) {
            _name = name_;
            _symbol = symbol_;
        }
        /**
         * @dev Returns the name of the token.
         */
        function name() public view virtual override returns (string memory) {
            return _name;
        }
        /**
         * @dev Returns the symbol of the token, usually a shorter version of the
         * name.
         */
        function symbol() public view virtual override returns (string memory) {
            return _symbol;
        }
        /**
         * @dev Returns the number of decimals used to get its user representation.
         * For example, if `decimals` equals `2`, a balance of `505` tokens should
         * be displayed to a user as `5.05` (`505 / 10 ** 2`).
         *
         * Tokens usually opt for a value of 18, imitating the relationship between
         * Ether and Wei. This is the default value returned by this function, unless
         * it's overridden.
         *
         * NOTE: This information is only used for _display_ purposes: it in
         * no way affects any of the arithmetic of the contract, including
         * {IERC20-balanceOf} and {IERC20-transfer}.
         */
        function decimals() public view virtual override returns (uint8) {
            return 18;
        }
        /**
         * @dev See {IERC20-totalSupply}.
         */
        function totalSupply() public view virtual override returns (uint256) {
            return _totalSupply;
        }
        /**
         * @dev See {IERC20-balanceOf}.
         */
        function balanceOf(address account) public view virtual override returns (uint256) {
            return _balances[account];
        }
        /**
         * @dev See {IERC20-transfer}.
         *
         * Requirements:
         *
         * - `to` cannot be the zero address.
         * - the caller must have a balance of at least `amount`.
         */
        function transfer(address to, uint256 amount) public virtual override returns (bool) {
            address owner = _msgSender();
            _transfer(owner, to, amount);
            return true;
        }
        /**
         * @dev See {IERC20-allowance}.
         */
        function allowance(address owner, address spender) public view virtual override returns (uint256) {
            return _allowances[owner][spender];
        }
        /**
         * @dev See {IERC20-approve}.
         *
         * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
         * `transferFrom`. This is semantically equivalent to an infinite approval.
         *
         * Requirements:
         *
         * - `spender` cannot be the zero address.
         */
        function approve(address spender, uint256 amount) public virtual override returns (bool) {
            address owner = _msgSender();
            _approve(owner, spender, amount);
            return true;
        }
        /**
         * @dev See {IERC20-transferFrom}.
         *
         * Emits an {Approval} event indicating the updated allowance. This is not
         * required by the EIP. See the note at the beginning of {ERC20}.
         *
         * NOTE: Does not update the allowance if the current allowance
         * is the maximum `uint256`.
         *
         * Requirements:
         *
         * - `from` and `to` cannot be the zero address.
         * - `from` must have a balance of at least `amount`.
         * - the caller must have allowance for ``from``'s tokens of at least
         * `amount`.
         */
        function transferFrom(address from, address to, uint256 amount) public virtual override returns (bool) {
            address spender = _msgSender();
            _spendAllowance(from, spender, amount);
            _transfer(from, to, amount);
            return true;
        }
        /**
         * @dev Atomically increases the allowance granted to `spender` by the caller.
         *
         * This is an alternative to {approve} that can be used as a mitigation for
         * problems described in {IERC20-approve}.
         *
         * Emits an {Approval} event indicating the updated allowance.
         *
         * Requirements:
         *
         * - `spender` cannot be the zero address.
         */
        function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
            address owner = _msgSender();
            _approve(owner, spender, allowance(owner, spender) + addedValue);
            return true;
        }
        /**
         * @dev Atomically decreases the allowance granted to `spender` by the caller.
         *
         * This is an alternative to {approve} that can be used as a mitigation for
         * problems described in {IERC20-approve}.
         *
         * Emits an {Approval} event indicating the updated allowance.
         *
         * Requirements:
         *
         * - `spender` cannot be the zero address.
         * - `spender` must have allowance for the caller of at least
         * `subtractedValue`.
         */
        function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
            address owner = _msgSender();
            uint256 currentAllowance = allowance(owner, spender);
            require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
            unchecked {
                _approve(owner, spender, currentAllowance - subtractedValue);
            }
            return true;
        }
        /**
         * @dev Moves `amount` of tokens from `from` to `to`.
         *
         * This internal function is equivalent to {transfer}, and can be used to
         * e.g. implement automatic token fees, slashing mechanisms, etc.
         *
         * Emits a {Transfer} event.
         *
         * Requirements:
         *
         * - `from` cannot be the zero address.
         * - `to` cannot be the zero address.
         * - `from` must have a balance of at least `amount`.
         */
        function _transfer(address from, address to, uint256 amount) internal virtual {
            require(from != address(0), "ERC20: transfer from the zero address");
            require(to != address(0), "ERC20: transfer to the zero address");
            _beforeTokenTransfer(from, to, amount);
            uint256 fromBalance = _balances[from];
            require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
            unchecked {
                _balances[from] = fromBalance - amount;
                // Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
                // decrementing then incrementing.
                _balances[to] += amount;
            }
            emit Transfer(from, to, amount);
            _afterTokenTransfer(from, to, amount);
        }
        /** @dev Creates `amount` tokens and assigns them to `account`, increasing
         * the total supply.
         *
         * Emits a {Transfer} event with `from` set to the zero address.
         *
         * Requirements:
         *
         * - `account` cannot be the zero address.
         */
        function _mint(address account, uint256 amount) internal virtual {
            require(account != address(0), "ERC20: mint to the zero address");
            _beforeTokenTransfer(address(0), account, amount);
            _totalSupply += amount;
            unchecked {
                // Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
                _balances[account] += amount;
            }
            emit Transfer(address(0), account, amount);
            _afterTokenTransfer(address(0), account, amount);
        }
        /**
         * @dev Destroys `amount` tokens from `account`, reducing the
         * total supply.
         *
         * Emits a {Transfer} event with `to` set to the zero address.
         *
         * Requirements:
         *
         * - `account` cannot be the zero address.
         * - `account` must have at least `amount` tokens.
         */
        function _burn(address account, uint256 amount) internal virtual {
            require(account != address(0), "ERC20: burn from the zero address");
            _beforeTokenTransfer(account, address(0), amount);
            uint256 accountBalance = _balances[account];
            require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
            unchecked {
                _balances[account] = accountBalance - amount;
                // Overflow not possible: amount <= accountBalance <= totalSupply.
                _totalSupply -= amount;
            }
            emit Transfer(account, address(0), amount);
            _afterTokenTransfer(account, address(0), amount);
        }
        /**
         * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
         *
         * This internal function is equivalent to `approve`, and can be used to
         * e.g. set automatic allowances for certain subsystems, etc.
         *
         * Emits an {Approval} event.
         *
         * Requirements:
         *
         * - `owner` cannot be the zero address.
         * - `spender` cannot be the zero address.
         */
        function _approve(address owner, address spender, uint256 amount) internal virtual {
            require(owner != address(0), "ERC20: approve from the zero address");
            require(spender != address(0), "ERC20: approve to the zero address");
            _allowances[owner][spender] = amount;
            emit Approval(owner, spender, amount);
        }
        /**
         * @dev Updates `owner` s allowance for `spender` based on spent `amount`.
         *
         * Does not update the allowance amount in case of infinite allowance.
         * Revert if not enough allowance is available.
         *
         * Might emit an {Approval} event.
         */
        function _spendAllowance(address owner, address spender, uint256 amount) internal virtual {
            uint256 currentAllowance = allowance(owner, spender);
            if (currentAllowance != type(uint256).max) {
                require(currentAllowance >= amount, "ERC20: insufficient allowance");
                unchecked {
                    _approve(owner, spender, currentAllowance - amount);
                }
            }
        }
        /**
         * @dev Hook that is called before any transfer of tokens. This includes
         * minting and burning.
         *
         * Calling conditions:
         *
         * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
         * will be transferred to `to`.
         * - when `from` is zero, `amount` tokens will be minted for `to`.
         * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
         * - `from` and `to` are never both zero.
         *
         * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
         */
        function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual {}
        /**
         * @dev Hook that is called after any transfer of tokens. This includes
         * minting and burning.
         *
         * Calling conditions:
         *
         * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
         * has been transferred to `to`.
         * - when `from` is zero, `amount` tokens have been minted for `to`.
         * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
         * - `from` and `to` are never both zero.
         *
         * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
         */
        function _afterTokenTransfer(address from, address to, uint256 amount) internal virtual {}
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)
    pragma solidity ^0.8.0;
    import "../IERC20.sol";
    /**
     * @dev Interface for the optional metadata functions from the ERC20 standard.
     *
     * _Available since v4.1._
     */
    interface IERC20Metadata is IERC20 {
        /**
         * @dev Returns the name of the token.
         */
        function name() external view returns (string memory);
        /**
         * @dev Returns the symbol of the token.
         */
        function symbol() external view returns (string memory);
        /**
         * @dev Returns the decimals places of the token.
         */
        function decimals() external view returns (uint8);
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)
    pragma solidity ^0.8.0;
    /**
     * @dev Interface of the ERC20 standard as defined in the EIP.
     */
    interface IERC20 {
        /**
         * @dev Emitted when `value` tokens are moved from one account (`from`) to
         * another (`to`).
         *
         * Note that `value` may be zero.
         */
        event Transfer(address indexed from, address indexed to, uint256 value);
        /**
         * @dev Emitted when the allowance of a `spender` for an `owner` is set by
         * a call to {approve}. `value` is the new allowance.
         */
        event Approval(address indexed owner, address indexed spender, uint256 value);
        /**
         * @dev Returns the amount of tokens in existence.
         */
        function totalSupply() external view returns (uint256);
        /**
         * @dev Returns the amount of tokens owned by `account`.
         */
        function balanceOf(address account) external view returns (uint256);
        /**
         * @dev Moves `amount` tokens from the caller's account to `to`.
         *
         * Returns a boolean value indicating whether the operation succeeded.
         *
         * Emits a {Transfer} event.
         */
        function transfer(address to, uint256 amount) external returns (bool);
        /**
         * @dev Returns the remaining number of tokens that `spender` will be
         * allowed to spend on behalf of `owner` through {transferFrom}. This is
         * zero by default.
         *
         * This value changes when {approve} or {transferFrom} are called.
         */
        function allowance(address owner, address spender) external view returns (uint256);
        /**
         * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
         *
         * Returns a boolean value indicating whether the operation succeeded.
         *
         * IMPORTANT: Beware that changing an allowance with this method brings the risk
         * that someone may use both the old and the new allowance by unfortunate
         * transaction ordering. One possible solution to mitigate this race
         * condition is to first reduce the spender's allowance to 0 and set the
         * desired value afterwards:
         * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
         *
         * Emits an {Approval} event.
         */
        function approve(address spender, uint256 amount) external returns (bool);
        /**
         * @dev Moves `amount` tokens from `from` to `to` using the
         * allowance mechanism. `amount` is then deducted from the caller's
         * allowance.
         *
         * Returns a boolean value indicating whether the operation succeeded.
         *
         * Emits a {Transfer} event.
         */
        function transferFrom(address from, address to, uint256 amount) external returns (bool);
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
    pragma solidity ^0.8.0;
    /**
     * @dev Provides information about the current execution context, including the
     * sender of the transaction and its data. While these are generally available
     * via msg.sender and msg.data, they should not be accessed in such a direct
     * manner, since when dealing with meta-transactions the account sending and
     * paying for execution may not be the actual sender (as far as an application
     * is concerned).
     *
     * This contract is only required for intermediate, library-like contracts.
     */
    abstract contract Context {
        function _msgSender() internal view virtual returns (address) {
            return msg.sender;
        }
        function _msgData() internal view virtual returns (bytes calldata) {
            return msg.data;
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
    pragma solidity ^0.8.0;
    import "./IERC165.sol";
    /**
     * @dev Implementation of the {IERC165} interface.
     *
     * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
     * for the additional interface id that will be supported. For example:
     *
     * ```solidity
     * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
     *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
     * }
     * ```
     *
     * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
     */
    abstract contract ERC165 is IERC165 {
        /**
         * @dev See {IERC165-supportsInterface}.
         */
        function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
            return interfaceId == type(IERC165).interfaceId;
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
    pragma solidity ^0.8.0;
    /**
     * @dev Interface of the ERC165 standard, as defined in the
     * https://eips.ethereum.org/EIPS/eip-165[EIP].
     *
     * Implementers can declare support of contract interfaces, which can then be
     * queried by others ({ERC165Checker}).
     *
     * For an implementation, see {ERC165}.
     */
    interface IERC165 {
        /**
         * @dev Returns true if this contract implements the interface defined by
         * `interfaceId`. See the corresponding
         * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
         * to learn more about how these ids are created.
         *
         * This function call must use less than 30 000 gas.
         */
        function supportsInterface(bytes4 interfaceId) external view returns (bool);
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.5.0;
    import "./ILayerZeroUserApplicationConfig.sol";
    interface ILayerZeroEndpoint is ILayerZeroUserApplicationConfig {
        // @notice send a LayerZero message to the specified address at a LayerZero endpoint.
        // @param _dstChainId - the destination chain identifier
        // @param _destination - the address on destination chain (in bytes). address length/format may vary by chains
        // @param _payload - a custom bytes payload to send to the destination contract
        // @param _refundAddress - if the source transaction is cheaper than the amount of value passed, refund the additional amount to this address
        // @param _zroPaymentAddress - the address of the ZRO token holder who would pay for the transaction
        // @param _adapterParams - parameters for custom functionality. e.g. receive airdropped native gas from the relayer on destination
        function send(uint16 _dstChainId, bytes calldata _destination, bytes calldata _payload, address payable _refundAddress, address _zroPaymentAddress, bytes calldata _adapterParams) external payable;
        // @notice used by the messaging library to publish verified payload
        // @param _srcChainId - the source chain identifier
        // @param _srcAddress - the source contract (as bytes) at the source chain
        // @param _dstAddress - the address on destination chain
        // @param _nonce - the unbound message ordering nonce
        // @param _gasLimit - the gas limit for external contract execution
        // @param _payload - verified payload to send to the destination contract
        function receivePayload(uint16 _srcChainId, bytes calldata _srcAddress, address _dstAddress, uint64 _nonce, uint _gasLimit, bytes calldata _payload) external;
        // @notice get the inboundNonce of a lzApp from a source chain which could be EVM or non-EVM chain
        // @param _srcChainId - the source chain identifier
        // @param _srcAddress - the source chain contract address
        function getInboundNonce(uint16 _srcChainId, bytes calldata _srcAddress) external view returns (uint64);
        // @notice get the outboundNonce from this source chain which, consequently, is always an EVM
        // @param _srcAddress - the source chain contract address
        function getOutboundNonce(uint16 _dstChainId, address _srcAddress) external view returns (uint64);
        // @notice gets a quote in source native gas, for the amount that send() requires to pay for message delivery
        // @param _dstChainId - the destination chain identifier
        // @param _userApplication - the user app address on this EVM chain
        // @param _payload - the custom message to send over LayerZero
        // @param _payInZRO - if false, user app pays the protocol fee in native token
        // @param _adapterParam - parameters for the adapter service, e.g. send some dust native token to dstChain
        function estimateFees(uint16 _dstChainId, address _userApplication, bytes calldata _payload, bool _payInZRO, bytes calldata _adapterParam) external view returns (uint nativeFee, uint zroFee);
        // @notice get this Endpoint's immutable source identifier
        function getChainId() external view returns (uint16);
        // @notice the interface to retry failed message on this Endpoint destination
        // @param _srcChainId - the source chain identifier
        // @param _srcAddress - the source chain contract address
        // @param _payload - the payload to be retried
        function retryPayload(uint16 _srcChainId, bytes calldata _srcAddress, bytes calldata _payload) external;
        // @notice query if any STORED payload (message blocking) at the endpoint.
        // @param _srcChainId - the source chain identifier
        // @param _srcAddress - the source chain contract address
        function hasStoredPayload(uint16 _srcChainId, bytes calldata _srcAddress) external view returns (bool);
        // @notice query if the _libraryAddress is valid for sending msgs.
        // @param _userApplication - the user app address on this EVM chain
        function getSendLibraryAddress(address _userApplication) external view returns (address);
        // @notice query if the _libraryAddress is valid for receiving msgs.
        // @param _userApplication - the user app address on this EVM chain
        function getReceiveLibraryAddress(address _userApplication) external view returns (address);
        // @notice query if the non-reentrancy guard for send() is on
        // @return true if the guard is on. false otherwise
        function isSendingPayload() external view returns (bool);
        // @notice query if the non-reentrancy guard for receive() is on
        // @return true if the guard is on. false otherwise
        function isReceivingPayload() external view returns (bool);
        // @notice get the configuration of the LayerZero messaging library of the specified version
        // @param _version - messaging library version
        // @param _chainId - the chainId for the pending config change
        // @param _userApplication - the contract address of the user application
        // @param _configType - type of configuration. every messaging library has its own convention.
        function getConfig(uint16 _version, uint16 _chainId, address _userApplication, uint _configType) external view returns (bytes memory);
        // @notice get the send() LayerZero messaging library version
        // @param _userApplication - the contract address of the user application
        function getSendVersion(address _userApplication) external view returns (uint16);
        // @notice get the lzReceive() LayerZero messaging library version
        // @param _userApplication - the contract address of the user application
        function getReceiveVersion(address _userApplication) external view returns (uint16);
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.5.0;
    interface ILayerZeroReceiver {
        // @notice LayerZero endpoint will invoke this function to deliver the message on the destination
        // @param _srcChainId - the source endpoint identifier
        // @param _srcAddress - the source sending contract address from the source chain
        // @param _nonce - the ordered message nonce
        // @param _payload - the signed payload is the UA bytes has encoded to be sent
        function lzReceive(uint16 _srcChainId, bytes calldata _srcAddress, uint64 _nonce, bytes calldata _payload) external;
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.5.0;
    interface ILayerZeroUserApplicationConfig {
        // @notice set the configuration of the LayerZero messaging library of the specified version
        // @param _version - messaging library version
        // @param _chainId - the chainId for the pending config change
        // @param _configType - type of configuration. every messaging library has its own convention.
        // @param _config - configuration in the bytes. can encode arbitrary content.
        function setConfig(uint16 _version, uint16 _chainId, uint _configType, bytes calldata _config) external;
        // @notice set the send() LayerZero messaging library version to _version
        // @param _version - new messaging library version
        function setSendVersion(uint16 _version) external;
        // @notice set the lzReceive() LayerZero messaging library version to _version
        // @param _version - new messaging library version
        function setReceiveVersion(uint16 _version) external;
        // @notice Only when the UA needs to resume the message flow in blocking mode and clear the stored payload
        // @param _srcChainId - the chainId of the source chain
        // @param _srcAddress - the contract address of the source contract at the source chain
        function forceResumeReceive(uint16 _srcChainId, bytes calldata _srcAddress) external;
    }
    // SPDX-License-Identifier: MIT
    pragma solidity 0.8.20;
    interface IOFTMintable {
        /**
         * @notice Mint tokens.
         * @dev Only callable by address with minter role.
         * @param _account Address to mint tokens to.
         * @param _amount Amount of tokens to mint.
         */
        function mint(address _account, uint256 _amount) external;
        /**
         * @notice Set minter role.
         * @param _minter address for adding or removing minter role.
         * @param _isMinter boolean value for defining minter role.
         */
        function setMinter(address _minter, bool _isMinter) external;
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    import "@openzeppelin/contracts/access/Ownable.sol";
    import "../interfaces/ILayerZeroReceiver.sol";
    import "../interfaces/ILayerZeroUserApplicationConfig.sol";
    import "../interfaces/ILayerZeroEndpoint.sol";
    import "../util/BytesLib.sol";
    /*
     * a generic LzReceiver implementation
     */
    abstract contract LzApp is
        Ownable,
        ILayerZeroReceiver,
        ILayerZeroUserApplicationConfig
    {
        using BytesLib for bytes;
        // ua can not send payload larger than this by default, but it can be changed by the ua owner
        uint public constant DEFAULT_PAYLOAD_SIZE_LIMIT = 10000;
        ILayerZeroEndpoint public immutable lzEndpoint;
        mapping(uint16 => bytes) public trustedRemoteLookup;
        mapping(uint16 => mapping(uint16 => uint)) public minDstGasLookup;
        mapping(uint16 => uint) public payloadSizeLimitLookup;
        address public precrime;
        event SetPrecrime(address precrime);
        event SetTrustedRemote(uint16 _remoteChainId, bytes _path);
        event SetTrustedRemoteAddress(uint16 _remoteChainId, bytes _remoteAddress);
        event SetMinDstGas(uint16 _dstChainId, uint16 _type, uint _minDstGas);
        constructor(address _endpoint) {
            lzEndpoint = ILayerZeroEndpoint(_endpoint);
        }
        function lzReceive(
            uint16 _srcChainId,
            bytes calldata _srcAddress,
            uint64 _nonce,
            bytes calldata _payload
        ) public virtual override {
            // lzReceive must be called by the endpoint for security
            require(
                _msgSender() == address(lzEndpoint),
                "LzApp: invalid endpoint caller"
            );
            bytes memory trustedRemote = trustedRemoteLookup[_srcChainId];
            // if will still block the message pathway from (srcChainId, srcAddress). should not receive message from untrusted remote.
            require(
                _srcAddress.length == trustedRemote.length &&
                    trustedRemote.length > 0 &&
                    keccak256(_srcAddress) == keccak256(trustedRemote),
                "LzApp: invalid source sending contract"
            );
            _blockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload);
        }
        // abstract function - the default behaviour of LayerZero is blocking. See: NonblockingLzApp if you dont need to enforce ordered messaging
        function _blockingLzReceive(
            uint16 _srcChainId,
            bytes memory _srcAddress,
            uint64 _nonce,
            bytes memory _payload
        ) internal virtual;
        function _lzSend(
            uint16 _dstChainId,
            bytes memory _payload,
            address payable _refundAddress,
            address _zroPaymentAddress,
            bytes memory _adapterParams,
            uint _nativeFee
        ) internal virtual {
            bytes memory trustedRemote = trustedRemoteLookup[_dstChainId];
            require(
                trustedRemote.length != 0,
                "LzApp: destination chain is not a trusted source"
            );
            _checkPayloadSize(_dstChainId, _payload.length);
            lzEndpoint.send{value: _nativeFee}(
                _dstChainId,
                trustedRemote,
                _payload,
                _refundAddress,
                _zroPaymentAddress,
                _adapterParams
            );
        }
        function _checkGasLimit(
            uint16 _dstChainId,
            uint16 _type,
            bytes memory _adapterParams,
            uint _extraGas
        ) internal view virtual {
            uint providedGasLimit = _getGasLimit(_adapterParams);
            uint minGasLimit = minDstGasLookup[_dstChainId][_type] + _extraGas;
            require(minGasLimit > 0, "LzApp: minGasLimit not set");
            require(providedGasLimit >= minGasLimit, "LzApp: gas limit is too low");
        }
        function _getGasLimit(
            bytes memory _adapterParams
        ) internal pure virtual returns (uint gasLimit) {
            require(_adapterParams.length >= 34, "LzApp: invalid adapterParams");
            assembly {
                gasLimit := mload(add(_adapterParams, 34))
            }
        }
        function _checkPayloadSize(
            uint16 _dstChainId,
            uint _payloadSize
        ) internal view virtual {
            uint payloadSizeLimit = payloadSizeLimitLookup[_dstChainId];
            if (payloadSizeLimit == 0) {
                // use default if not set
                payloadSizeLimit = DEFAULT_PAYLOAD_SIZE_LIMIT;
            }
            require(
                _payloadSize <= payloadSizeLimit,
                "LzApp: payload size is too large"
            );
        }
        //---------------------------UserApplication config----------------------------------------
        function getConfig(
            uint16 _version,
            uint16 _chainId,
            address,
            uint _configType
        ) external view returns (bytes memory) {
            return
                lzEndpoint.getConfig(
                    _version,
                    _chainId,
                    address(this),
                    _configType
                );
        }
        // generic config for LayerZero user Application
        function setConfig(
            uint16 _version,
            uint16 _chainId,
            uint _configType,
            bytes calldata _config
        ) external override onlyOwner {
            lzEndpoint.setConfig(_version, _chainId, _configType, _config);
        }
        function setSendVersion(uint16 _version) external override onlyOwner {
            lzEndpoint.setSendVersion(_version);
        }
        function setReceiveVersion(uint16 _version) external override onlyOwner {
            lzEndpoint.setReceiveVersion(_version);
        }
        function forceResumeReceive(
            uint16 _srcChainId,
            bytes calldata _srcAddress
        ) external override onlyOwner {
            lzEndpoint.forceResumeReceive(_srcChainId, _srcAddress);
        }
        // _path = abi.encodePacked(remoteAddress, localAddress)
        // this function set the trusted path for the cross-chain communication
        function setTrustedRemote(
            uint16 _remoteChainId,
            bytes calldata _path
        ) external onlyOwner {
            trustedRemoteLookup[_remoteChainId] = _path;
            emit SetTrustedRemote(_remoteChainId, _path);
        }
        function setTrustedRemoteAddress(
            uint16 _remoteChainId,
            bytes calldata _remoteAddress
        ) external onlyOwner {
            trustedRemoteLookup[_remoteChainId] = abi.encodePacked(
                _remoteAddress,
                address(this)
            );
            emit SetTrustedRemoteAddress(_remoteChainId, _remoteAddress);
        }
        function getTrustedRemoteAddress(
            uint16 _remoteChainId
        ) external view returns (bytes memory) {
            bytes memory path = trustedRemoteLookup[_remoteChainId];
            require(path.length != 0, "LzApp: no trusted path record");
            return path.slice(0, path.length - 20); // the last 20 bytes should be address(this)
        }
        function setPrecrime(address _precrime) external onlyOwner {
            precrime = _precrime;
            emit SetPrecrime(_precrime);
        }
        function setMinDstGas(
            uint16 _dstChainId,
            uint16 _packetType,
            uint _minGas
        ) external onlyOwner {
            require(_minGas > 0, "LzApp: invalid minGas");
            minDstGasLookup[_dstChainId][_packetType] = _minGas;
            emit SetMinDstGas(_dstChainId, _packetType, _minGas);
        }
        // if the size is 0, it means default size limit
        function setPayloadSizeLimit(
            uint16 _dstChainId,
            uint _size
        ) external onlyOwner {
            payloadSizeLimitLookup[_dstChainId] = _size;
        }
        //--------------------------- VIEW FUNCTION ----------------------------------------
        function isTrustedRemote(
            uint16 _srcChainId,
            bytes calldata _srcAddress
        ) external view returns (bool) {
            bytes memory trustedSource = trustedRemoteLookup[_srcChainId];
            return keccak256(trustedSource) == keccak256(_srcAddress);
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    import "./LzApp.sol";
    import "../util/ExcessivelySafeCall.sol";
    /*
     * the default LayerZero messaging behaviour is blocking, i.e. any failed message will block the channel
     * this abstract class try-catch all fail messages and store locally for future retry. hence, non-blocking
     * NOTE: if the srcAddress is not configured properly, it will still block the message pathway from (srcChainId, srcAddress)
     */
    abstract contract NonblockingLzApp is LzApp {
        using ExcessivelySafeCall for address;
        constructor(address _endpoint) LzApp(_endpoint) {}
        mapping(uint16 => mapping(bytes => mapping(uint64 => bytes32)))
            public failedMessages;
        event MessageFailed(
            uint16 _srcChainId,
            bytes _srcAddress,
            uint64 _nonce,
            bytes _payload,
            bytes _reason
        );
        event RetryMessageSuccess(
            uint16 _srcChainId,
            bytes _srcAddress,
            uint64 _nonce,
            bytes32 _payloadHash
        );
        // overriding the virtual function in LzReceiver
        function _blockingLzReceive(
            uint16 _srcChainId,
            bytes memory _srcAddress,
            uint64 _nonce,
            bytes memory _payload
        ) internal virtual override {
            (bool success, bytes memory reason) = address(this).excessivelySafeCall(
                gasleft(),
                150,
                abi.encodeWithSelector(
                    this.nonblockingLzReceive.selector,
                    _srcChainId,
                    _srcAddress,
                    _nonce,
                    _payload
                )
            );
            // try-catch all errors/exceptions
            if (!success) {
                _storeFailedMessage(
                    _srcChainId,
                    _srcAddress,
                    _nonce,
                    _payload,
                    reason
                );
            }
        }
        function _storeFailedMessage(
            uint16 _srcChainId,
            bytes memory _srcAddress,
            uint64 _nonce,
            bytes memory _payload,
            bytes memory _reason
        ) internal virtual {
            failedMessages[_srcChainId][_srcAddress][_nonce] = keccak256(_payload);
            emit MessageFailed(_srcChainId, _srcAddress, _nonce, _payload, _reason);
        }
        function nonblockingLzReceive(
            uint16 _srcChainId,
            bytes calldata _srcAddress,
            uint64 _nonce,
            bytes calldata _payload
        ) public virtual {
            // only internal transaction
            require(
                _msgSender() == address(this),
                "NonblockingLzApp: caller must be LzApp"
            );
            _nonblockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload);
        }
        //@notice override this function
        function _nonblockingLzReceive(
            uint16 _srcChainId,
            bytes memory _srcAddress,
            uint64 _nonce,
            bytes memory _payload
        ) internal virtual;
        function retryMessage(
            uint16 _srcChainId,
            bytes calldata _srcAddress,
            uint64 _nonce,
            bytes calldata _payload
        ) public payable virtual {
            // assert there is message to retry
            bytes32 payloadHash = failedMessages[_srcChainId][_srcAddress][_nonce];
            require(
                payloadHash != bytes32(0),
                "NonblockingLzApp: no stored message"
            );
            require(
                keccak256(_payload) == payloadHash,
                "NonblockingLzApp: invalid payload"
            );
            // clear the stored message
            failedMessages[_srcChainId][_srcAddress][_nonce] = bytes32(0);
            // execute the message. revert if it fails again
            _nonblockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload);
            emit RetryMessageSuccess(_srcChainId, _srcAddress, _nonce, payloadHash);
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.5.0;
    import "./IOFTCore.sol";
    import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
    /**
     * @dev Interface of the OFT standard
     */
    interface IOFT is IOFTCore, IERC20 {
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.5.0;
    import "@openzeppelin/contracts/utils/introspection/IERC165.sol";
    /**
     * @dev Interface of the IOFT core standard
     */
    interface IOFTCore is IERC165 {
        /**
         * @dev estimate send token `_tokenId` to (`_dstChainId`, `_toAddress`)
         * _dstChainId - L0 defined chain id to send tokens too
         * _toAddress - dynamic bytes array which contains the address to whom you are sending tokens to on the dstChain
         * _amount - amount of the tokens to transfer
         * _useZro - indicates to use zro to pay L0 fees
         * _adapterParam - flexible bytes array to indicate messaging adapter services in L0
         */
        function estimateSendFee(uint16 _dstChainId, bytes calldata _toAddress, uint _amount, bool _useZro, bytes calldata _adapterParams) external view returns (uint nativeFee, uint zroFee);
        /**
         * @dev send `_amount` amount of token to (`_dstChainId`, `_toAddress`) from `_from`
         * `_from` the owner of token
         * `_dstChainId` the destination chain identifier
         * `_toAddress` can be any size depending on the `dstChainId`.
         * `_amount` the quantity of tokens in wei
         * `_refundAddress` the address LayerZero refunds if too much message fee is sent
         * `_zroPaymentAddress` set to address(0x0) if not paying in ZRO (LayerZero Token)
         * `_adapterParams` is a flexible bytes array to indicate messaging adapter services
         */
        function sendFrom(address _from, uint16 _dstChainId, bytes calldata _toAddress, uint _amount, address payable _refundAddress, address _zroPaymentAddress, bytes calldata _adapterParams) external payable;
        /**
         * @dev returns the circulating amount of tokens on current chain
         */
        function circulatingSupply() external view returns (uint);
        /**
         * @dev returns the address of the ERC20 token
         */
        function token() external view returns (address);
        /**
         * @dev Emitted when `_amount` tokens are moved from the `_sender` to (`_dstChainId`, `_toAddress`)
         * `_nonce` is the outbound nonce
         */
        event SendToChain(uint16 indexed _dstChainId, address indexed _from, bytes _toAddress, uint _amount);
        /**
         * @dev Emitted when `_amount` tokens are received from `_srcChainId` into the `_toAddress` on the local chain.
         * `_nonce` is the inbound nonce.
         */
        event ReceiveFromChain(uint16 indexed _srcChainId, address indexed _to, uint _amount);
        event SetUseCustomAdapterParams(bool _useCustomAdapterParams);
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
    import "@openzeppelin/contracts/utils/introspection/IERC165.sol";
    import "./IOFT.sol";
    import "./OFTCore.sol";
    // override decimal() function is needed
    contract OFT is OFTCore, ERC20, IOFT {
        constructor(
            string memory _name,
            string memory _symbol,
            address _lzEndpoint
        ) ERC20(_name, _symbol) OFTCore(_lzEndpoint) {}
        function supportsInterface(
            bytes4 interfaceId
        ) public view virtual override(OFTCore, IERC165) returns (bool) {
            return
                interfaceId == type(IOFT).interfaceId ||
                interfaceId == type(IERC20).interfaceId ||
                super.supportsInterface(interfaceId);
        }
        function token() public view virtual override returns (address) {
            return address(this);
        }
        function circulatingSupply() public view virtual override returns (uint) {
            return totalSupply();
        }
        function _debitFrom(
            address _from,
            uint16,
            bytes memory,
            uint _amount
        ) internal virtual override returns (uint) {
            address spender = _msgSender();
            if (_from != spender) _spendAllowance(_from, spender, _amount);
            _burn(_from, _amount);
            return _amount;
        }
        function _creditTo(
            uint16,
            address _toAddress,
            uint _amount
        ) internal virtual override returns (uint) {
            _mint(_toAddress, _amount);
            return _amount;
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    import "../lzApp/NonblockingLzApp.sol";
    import "./IOFTCore.sol";
    import "@openzeppelin/contracts/utils/introspection/ERC165.sol";
    abstract contract OFTCore is NonblockingLzApp, ERC165, IOFTCore {
        using BytesLib for bytes;
        uint public constant NO_EXTRA_GAS = 0;
        // packet type
        uint16 public constant PT_SEND = 0;
        bool public useCustomAdapterParams;
        constructor(address _lzEndpoint) NonblockingLzApp(_lzEndpoint) {}
        function supportsInterface(
            bytes4 interfaceId
        ) public view virtual override(ERC165, IERC165) returns (bool) {
            return
                interfaceId == type(IOFTCore).interfaceId ||
                super.supportsInterface(interfaceId);
        }
        function estimateSendFee(
            uint16 _dstChainId,
            bytes calldata _toAddress,
            uint _amount,
            bool _useZro,
            bytes calldata _adapterParams
        ) public view virtual override returns (uint nativeFee, uint zroFee) {
            // mock the payload for sendFrom()
            bytes memory payload = abi.encode(PT_SEND, _toAddress, _amount);
            return
                lzEndpoint.estimateFees(
                    _dstChainId,
                    address(this),
                    payload,
                    _useZro,
                    _adapterParams
                );
        }
        function sendFrom(
            address _from,
            uint16 _dstChainId,
            bytes calldata _toAddress,
            uint _amount,
            address payable _refundAddress,
            address _zroPaymentAddress,
            bytes calldata _adapterParams
        ) public payable virtual override {
            _send(
                _from,
                _dstChainId,
                _toAddress,
                _amount,
                _refundAddress,
                _zroPaymentAddress,
                _adapterParams
            );
        }
        function setUseCustomAdapterParams(
            bool _useCustomAdapterParams
        ) public virtual onlyOwner {
            useCustomAdapterParams = _useCustomAdapterParams;
            emit SetUseCustomAdapterParams(_useCustomAdapterParams);
        }
        function _nonblockingLzReceive(
            uint16 _srcChainId,
            bytes memory _srcAddress,
            uint64 _nonce,
            bytes memory _payload
        ) internal virtual override {
            uint16 packetType;
            assembly {
                packetType := mload(add(_payload, 32))
            }
            if (packetType == PT_SEND) {
                _sendAck(_srcChainId, _srcAddress, _nonce, _payload);
            } else {
                revert("OFTCore: unknown packet type");
            }
        }
        function _send(
            address _from,
            uint16 _dstChainId,
            bytes memory _toAddress,
            uint _amount,
            address payable _refundAddress,
            address _zroPaymentAddress,
            bytes memory _adapterParams
        ) internal virtual {
            _checkAdapterParams(_dstChainId, PT_SEND, _adapterParams, NO_EXTRA_GAS);
            uint amount = _debitFrom(_from, _dstChainId, _toAddress, _amount);
            bytes memory lzPayload = abi.encode(PT_SEND, _toAddress, amount);
            _lzSend(
                _dstChainId,
                lzPayload,
                _refundAddress,
                _zroPaymentAddress,
                _adapterParams,
                msg.value
            );
            emit SendToChain(_dstChainId, _from, _toAddress, amount);
        }
        function _sendAck(
            uint16 _srcChainId,
            bytes memory,
            uint64,
            bytes memory _payload
        ) internal virtual {
            (, bytes memory toAddressBytes, uint amount) = abi.decode(
                _payload,
                (uint16, bytes, uint)
            );
            address to = toAddressBytes.toAddress(0);
            amount = _creditTo(_srcChainId, to, amount);
            emit ReceiveFromChain(_srcChainId, to, amount);
        }
        function _checkAdapterParams(
            uint16 _dstChainId,
            uint16 _pkType,
            bytes memory _adapterParams,
            uint _extraGas
        ) internal virtual {
            if (useCustomAdapterParams) {
                _checkGasLimit(_dstChainId, _pkType, _adapterParams, _extraGas);
            } else {
                require(
                    _adapterParams.length == 0,
                    "OFTCore: _adapterParams must be empty."
                );
            }
        }
        function _debitFrom(
            address _from,
            uint16 _dstChainId,
            bytes memory _toAddress,
            uint _amount
        ) internal virtual returns (uint);
        function _creditTo(
            uint16 _srcChainId,
            address _toAddress,
            uint _amount
        ) internal virtual returns (uint);
    }
    // SPDX-License-Identifier: MIT
    pragma solidity 0.8.20;
    import "./IOFTMintable.sol";
    import "./oft/OFT.sol";
    /**
     * @title OFTMintable
     * @notice OFT token with minting and burning logic.
     */
    contract OFTMintable is OFT, IOFTMintable {
        /// @notice Minter addresses.
        mapping(address => bool) public minters;
        /// @notice Status of minting.
        /// @dev Can be kill-switched by the owner.
        bool public mintingEnabled = true;
        /**
         * @notice Event emitted when minter role is set.
         * @param account Address with minter role.
         * @param isMinter Status of minter role.
         */
        event SetMinter(address indexed account, bool isMinter);
        /**
         * @notice Event emitted when minting is disabled.
         * @dev After this event is emitted, minting is disabled forever.
         */
        event MintingDisabled();
        /**
         * @notice Constructor.
         * @param _layerZeroEndpoint Address of layerzero endpoint.
         * @param _name Token name.
         * @param _symbol Token symbol.
         */
        constructor(
            address _layerZeroEndpoint,
            string memory _name,
            string memory _symbol
        ) OFT(_name, _symbol, _layerZeroEndpoint) {}
        ///////////////////////
        /// User Functions  ///
        ///////////////////////
        /**
         * @inheritdoc IOFTMintable
         */
        function mint(address _account, uint256 _amount) external {
            require(mintingEnabled, "Minting disabled");
            require(minters[msg.sender], "Invalid minter");
            _mint(_account, _amount);
        }
        /**
         * @notice Burn tokens.
         * @dev It burns tokens of the msg.sender.
         * @param _amount Amount of tokens to burn.
         */
        function burn(uint256 _amount) external {
            _burn(msg.sender, _amount);
        }
        ///////////////////////
        /// Owner Functions ///
        ///////////////////////
        /**
         * @notice Disable minting.
         * @dev Can be only called by the owner, effectively only once.
         * @dev It only affects minting, on single chain.
         */
        function disableMinting() external onlyOwner {
            mintingEnabled = false;
            emit MintingDisabled();
        }
        /**
         * @inheritdoc IOFTMintable
         */
        function setMinter(address _minter, bool _isMinter) external onlyOwner {
            minters[_minter] = _isMinter;
            emit SetMinter(_minter, _isMinter);
        }
    }
    // SPDX-License-Identifier: Unlicense
    /*
     * @title Solidity Bytes Arrays Utils
     * @author Gonçalo Sá <goncalo.sa@consensys.net>
     *
     * @dev Bytes tightly packed arrays utility library for ethereum contracts written in Solidity.
     *      The library lets you concatenate, slice and type cast bytes arrays both in memory and storage.
     */
    pragma solidity >=0.8.0 <0.9.0;
    library BytesLib {
        function concat(
            bytes memory _preBytes,
            bytes memory _postBytes
        )
        internal
        pure
        returns (bytes memory)
        {
            bytes memory tempBytes;
            assembly {
            // Get a location of some free memory and store it in tempBytes as
            // Solidity does for memory variables.
                tempBytes := mload(0x40)
            // Store the length of the first bytes array at the beginning of
            // the memory for tempBytes.
                let length := mload(_preBytes)
                mstore(tempBytes, length)
            // Maintain a memory counter for the current write location in the
            // temp bytes array by adding the 32 bytes for the array length to
            // the starting location.
                let mc := add(tempBytes, 0x20)
            // Stop copying when the memory counter reaches the length of the
            // first bytes array.
                let end := add(mc, length)
                for {
                // Initialize a copy counter to the start of the _preBytes data,
                // 32 bytes into its memory.
                    let cc := add(_preBytes, 0x20)
                } lt(mc, end) {
                // Increase both counters by 32 bytes each iteration.
                    mc := add(mc, 0x20)
                    cc := add(cc, 0x20)
                } {
                // Write the _preBytes data into the tempBytes memory 32 bytes
                // at a time.
                    mstore(mc, mload(cc))
                }
            // Add the length of _postBytes to the current length of tempBytes
            // and store it as the new length in the first 32 bytes of the
            // tempBytes memory.
                length := mload(_postBytes)
                mstore(tempBytes, add(length, mload(tempBytes)))
            // Move the memory counter back from a multiple of 0x20 to the
            // actual end of the _preBytes data.
                mc := end
            // Stop copying when the memory counter reaches the new combined
            // length of the arrays.
                end := add(mc, length)
                for {
                    let cc := add(_postBytes, 0x20)
                } lt(mc, end) {
                    mc := add(mc, 0x20)
                    cc := add(cc, 0x20)
                } {
                    mstore(mc, mload(cc))
                }
            // Update the free-memory pointer by padding our last write location
            // to 32 bytes: add 31 bytes to the end of tempBytes to move to the
            // next 32 byte block, then round down to the nearest multiple of
            // 32. If the sum of the length of the two arrays is zero then add
            // one before rounding down to leave a blank 32 bytes (the length block with 0).
                mstore(0x40, and(
                add(add(end, iszero(add(length, mload(_preBytes)))), 31),
                not(31) // Round down to the nearest 32 bytes.
                ))
            }
            return tempBytes;
        }
        function concatStorage(bytes storage _preBytes, bytes memory _postBytes) internal {
            assembly {
            // Read the first 32 bytes of _preBytes storage, which is the length
            // of the array. (We don't need to use the offset into the slot
            // because arrays use the entire slot.)
                let fslot := sload(_preBytes.slot)
            // Arrays of 31 bytes or less have an even value in their slot,
            // while longer arrays have an odd value. The actual length is
            // the slot divided by two for odd values, and the lowest order
            // byte divided by two for even values.
            // If the slot is even, bitwise and the slot with 255 and divide by
            // two to get the length. If the slot is odd, bitwise and the slot
            // with -1 and divide by two.
                let slength := div(and(fslot, sub(mul(0x100, iszero(and(fslot, 1))), 1)), 2)
                let mlength := mload(_postBytes)
                let newlength := add(slength, mlength)
            // slength can contain both the length and contents of the array
            // if length < 32 bytes so let's prepare for that
            // v. http://solidity.readthedocs.io/en/latest/miscellaneous.html#layout-of-state-variables-in-storage
                switch add(lt(slength, 32), lt(newlength, 32))
                case 2 {
                // Since the new array still fits in the slot, we just need to
                // update the contents of the slot.
                // uint256(bytes_storage) = uint256(bytes_storage) + uint256(bytes_memory) + new_length
                    sstore(
                    _preBytes.slot,
                    // all the modifications to the slot are inside this
                    // next block
                    add(
                    // we can just add to the slot contents because the
                    // bytes we want to change are the LSBs
                    fslot,
                    add(
                    mul(
                    div(
                    // load the bytes from memory
                    mload(add(_postBytes, 0x20)),
                    // zero all bytes to the right
                    exp(0x100, sub(32, mlength))
                    ),
                    // and now shift left the number of bytes to
                    // leave space for the length in the slot
                    exp(0x100, sub(32, newlength))
                    ),
                    // increase length by the double of the memory
                    // bytes length
                    mul(mlength, 2)
                    )
                    )
                    )
                }
                case 1 {
                // The stored value fits in the slot, but the combined value
                // will exceed it.
                // get the keccak hash to get the contents of the array
                    mstore(0x0, _preBytes.slot)
                    let sc := add(keccak256(0x0, 0x20), div(slength, 32))
                // save new length
                    sstore(_preBytes.slot, add(mul(newlength, 2), 1))
                // The contents of the _postBytes array start 32 bytes into
                // the structure. Our first read should obtain the `submod`
                // bytes that can fit into the unused space in the last word
                // of the stored array. To get this, we read 32 bytes starting
                // from `submod`, so the data we read overlaps with the array
                // contents by `submod` bytes. Masking the lowest-order
                // `submod` bytes allows us to add that value directly to the
                // stored value.
                    let submod := sub(32, slength)
                    let mc := add(_postBytes, submod)
                    let end := add(_postBytes, mlength)
                    let mask := sub(exp(0x100, submod), 1)
                    sstore(
                    sc,
                    add(
                    and(
                    fslot,
                    0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff00
                    ),
                    and(mload(mc), mask)
                    )
                    )
                    for {
                        mc := add(mc, 0x20)
                        sc := add(sc, 1)
                    } lt(mc, end) {
                        sc := add(sc, 1)
                        mc := add(mc, 0x20)
                    } {
                        sstore(sc, mload(mc))
                    }
                    mask := exp(0x100, sub(mc, end))
                    sstore(sc, mul(div(mload(mc), mask), mask))
                }
                default {
                // get the keccak hash to get the contents of the array
                    mstore(0x0, _preBytes.slot)
                // Start copying to the last used word of the stored array.
                    let sc := add(keccak256(0x0, 0x20), div(slength, 32))
                // save new length
                    sstore(_preBytes.slot, add(mul(newlength, 2), 1))
                // Copy over the first `submod` bytes of the new data as in
                // case 1 above.
                    let slengthmod := mod(slength, 32)
                    let mlengthmod := mod(mlength, 32)
                    let submod := sub(32, slengthmod)
                    let mc := add(_postBytes, submod)
                    let end := add(_postBytes, mlength)
                    let mask := sub(exp(0x100, submod), 1)
                    sstore(sc, add(sload(sc), and(mload(mc), mask)))
                    for {
                        sc := add(sc, 1)
                        mc := add(mc, 0x20)
                    } lt(mc, end) {
                        sc := add(sc, 1)
                        mc := add(mc, 0x20)
                    } {
                        sstore(sc, mload(mc))
                    }
                    mask := exp(0x100, sub(mc, end))
                    sstore(sc, mul(div(mload(mc), mask), mask))
                }
            }
        }
        function slice(
            bytes memory _bytes,
            uint256 _start,
            uint256 _length
        )
        internal
        pure
        returns (bytes memory)
        {
            require(_length + 31 >= _length, "slice_overflow");
            require(_bytes.length >= _start + _length, "slice_outOfBounds");
            bytes memory tempBytes;
            assembly {
                switch iszero(_length)
                case 0 {
                // Get a location of some free memory and store it in tempBytes as
                // Solidity does for memory variables.
                    tempBytes := mload(0x40)
                // The first word of the slice result is potentially a partial
                // word read from the original array. To read it, we calculate
                // the length of that partial word and start copying that many
                // bytes into the array. The first word we copy will start with
                // data we don't care about, but the last `lengthmod` bytes will
                // land at the beginning of the contents of the new array. When
                // we're done copying, we overwrite the full first word with
                // the actual length of the slice.
                    let lengthmod := and(_length, 31)
                // The multiplication in the next line is necessary
                // because when slicing multiples of 32 bytes (lengthmod == 0)
                // the following copy loop was copying the origin's length
                // and then ending prematurely not copying everything it should.
                    let mc := add(add(tempBytes, lengthmod), mul(0x20, iszero(lengthmod)))
                    let end := add(mc, _length)
                    for {
                    // The multiplication in the next line has the same exact purpose
                    // as the one above.
                        let cc := add(add(add(_bytes, lengthmod), mul(0x20, iszero(lengthmod))), _start)
                    } lt(mc, end) {
                        mc := add(mc, 0x20)
                        cc := add(cc, 0x20)
                    } {
                        mstore(mc, mload(cc))
                    }
                    mstore(tempBytes, _length)
                //update free-memory pointer
                //allocating the array padded to 32 bytes like the compiler does now
                    mstore(0x40, and(add(mc, 31), not(31)))
                }
                //if we want a zero-length slice let's just return a zero-length array
                default {
                    tempBytes := mload(0x40)
                //zero out the 32 bytes slice we are about to return
                //we need to do it because Solidity does not garbage collect
                    mstore(tempBytes, 0)
                    mstore(0x40, add(tempBytes, 0x20))
                }
            }
            return tempBytes;
        }
        function toAddress(bytes memory _bytes, uint256 _start) internal pure returns (address) {
            require(_bytes.length >= _start + 20, "toAddress_outOfBounds");
            address tempAddress;
            assembly {
                tempAddress := div(mload(add(add(_bytes, 0x20), _start)), 0x1000000000000000000000000)
            }
            return tempAddress;
        }
        function toUint8(bytes memory _bytes, uint256 _start) internal pure returns (uint8) {
            require(_bytes.length >= _start + 1 , "toUint8_outOfBounds");
            uint8 tempUint;
            assembly {
                tempUint := mload(add(add(_bytes, 0x1), _start))
            }
            return tempUint;
        }
        function toUint16(bytes memory _bytes, uint256 _start) internal pure returns (uint16) {
            require(_bytes.length >= _start + 2, "toUint16_outOfBounds");
            uint16 tempUint;
            assembly {
                tempUint := mload(add(add(_bytes, 0x2), _start))
            }
            return tempUint;
        }
        function toUint32(bytes memory _bytes, uint256 _start) internal pure returns (uint32) {
            require(_bytes.length >= _start + 4, "toUint32_outOfBounds");
            uint32 tempUint;
            assembly {
                tempUint := mload(add(add(_bytes, 0x4), _start))
            }
            return tempUint;
        }
        function toUint64(bytes memory _bytes, uint256 _start) internal pure returns (uint64) {
            require(_bytes.length >= _start + 8, "toUint64_outOfBounds");
            uint64 tempUint;
            assembly {
                tempUint := mload(add(add(_bytes, 0x8), _start))
            }
            return tempUint;
        }
        function toUint96(bytes memory _bytes, uint256 _start) internal pure returns (uint96) {
            require(_bytes.length >= _start + 12, "toUint96_outOfBounds");
            uint96 tempUint;
            assembly {
                tempUint := mload(add(add(_bytes, 0xc), _start))
            }
            return tempUint;
        }
        function toUint128(bytes memory _bytes, uint256 _start) internal pure returns (uint128) {
            require(_bytes.length >= _start + 16, "toUint128_outOfBounds");
            uint128 tempUint;
            assembly {
                tempUint := mload(add(add(_bytes, 0x10), _start))
            }
            return tempUint;
        }
        function toUint256(bytes memory _bytes, uint256 _start) internal pure returns (uint256) {
            require(_bytes.length >= _start + 32, "toUint256_outOfBounds");
            uint256 tempUint;
            assembly {
                tempUint := mload(add(add(_bytes, 0x20), _start))
            }
            return tempUint;
        }
        function toBytes32(bytes memory _bytes, uint256 _start) internal pure returns (bytes32) {
            require(_bytes.length >= _start + 32, "toBytes32_outOfBounds");
            bytes32 tempBytes32;
            assembly {
                tempBytes32 := mload(add(add(_bytes, 0x20), _start))
            }
            return tempBytes32;
        }
        function equal(bytes memory _preBytes, bytes memory _postBytes) internal pure returns (bool) {
            bool success = true;
            assembly {
                let length := mload(_preBytes)
            // if lengths don't match the arrays are not equal
                switch eq(length, mload(_postBytes))
                case 1 {
                // cb is a circuit breaker in the for loop since there's
                //  no said feature for inline assembly loops
                // cb = 1 - don't breaker
                // cb = 0 - break
                    let cb := 1
                    let mc := add(_preBytes, 0x20)
                    let end := add(mc, length)
                    for {
                        let cc := add(_postBytes, 0x20)
                    // the next line is the loop condition:
                    // while(uint256(mc < end) + cb == 2)
                    } eq(add(lt(mc, end), cb), 2) {
                        mc := add(mc, 0x20)
                        cc := add(cc, 0x20)
                    } {
                    // if any of these checks fails then arrays are not equal
                        if iszero(eq(mload(mc), mload(cc))) {
                        // unsuccess:
                            success := 0
                            cb := 0
                        }
                    }
                }
                default {
                // unsuccess:
                    success := 0
                }
            }
            return success;
        }
        function equalStorage(
            bytes storage _preBytes,
            bytes memory _postBytes
        )
        internal
        view
        returns (bool)
        {
            bool success = true;
            assembly {
            // we know _preBytes_offset is 0
                let fslot := sload(_preBytes.slot)
            // Decode the length of the stored array like in concatStorage().
                let slength := div(and(fslot, sub(mul(0x100, iszero(and(fslot, 1))), 1)), 2)
                let mlength := mload(_postBytes)
            // if lengths don't match the arrays are not equal
                switch eq(slength, mlength)
                case 1 {
                // slength can contain both the length and contents of the array
                // if length < 32 bytes so let's prepare for that
                // v. http://solidity.readthedocs.io/en/latest/miscellaneous.html#layout-of-state-variables-in-storage
                    if iszero(iszero(slength)) {
                        switch lt(slength, 32)
                        case 1 {
                        // blank the last byte which is the length
                            fslot := mul(div(fslot, 0x100), 0x100)
                            if iszero(eq(fslot, mload(add(_postBytes, 0x20)))) {
                            // unsuccess:
                                success := 0
                            }
                        }
                        default {
                        // cb is a circuit breaker in the for loop since there's
                        //  no said feature for inline assembly loops
                        // cb = 1 - don't breaker
                        // cb = 0 - break
                            let cb := 1
                        // get the keccak hash to get the contents of the array
                            mstore(0x0, _preBytes.slot)
                            let sc := keccak256(0x0, 0x20)
                            let mc := add(_postBytes, 0x20)
                            let end := add(mc, mlength)
                        // the next line is the loop condition:
                        // while(uint256(mc < end) + cb == 2)
                            for {} eq(add(lt(mc, end), cb), 2) {
                                sc := add(sc, 1)
                                mc := add(mc, 0x20)
                            } {
                                if iszero(eq(sload(sc), mload(mc))) {
                                // unsuccess:
                                    success := 0
                                    cb := 0
                                }
                            }
                        }
                    }
                }
                default {
                // unsuccess:
                    success := 0
                }
            }
            return success;
        }
    }
    // SPDX-License-Identifier: MIT OR Apache-2.0
    pragma solidity >=0.7.6;
    library ExcessivelySafeCall {
        uint256 constant LOW_28_MASK =
        0x00000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffff;
        /// @notice Use when you _really_ really _really_ don't trust the called
        /// contract. This prevents the called contract from causing reversion of
        /// the caller in as many ways as we can.
        /// @dev The main difference between this and a solidity low-level call is
        /// that we limit the number of bytes that the callee can cause to be
        /// copied to caller memory. This prevents stupid things like malicious
        /// contracts returning 10,000,000 bytes causing a local OOG when copying
        /// to memory.
        /// @param _target The address to call
        /// @param _gas The amount of gas to forward to the remote contract
        /// @param _maxCopy The maximum number of bytes of returndata to copy
        /// to memory.
        /// @param _calldata The data to send to the remote contract
        /// @return success and returndata, as `.call()`. Returndata is capped to
        /// `_maxCopy` bytes.
        function excessivelySafeCall(
            address _target,
            uint256 _gas,
            uint16 _maxCopy,
            bytes memory _calldata
        ) internal returns (bool, bytes memory) {
            // set up for assembly call
            uint256 _toCopy;
            bool _success;
            bytes memory _returnData = new bytes(_maxCopy);
            // dispatch message to recipient
            // by assembly calling "handle" function
            // we call via assembly to avoid memcopying a very large returndata
            // returned by a malicious contract
            assembly {
                _success := call(
                _gas, // gas
                _target, // recipient
                0, // ether value
                add(_calldata, 0x20), // inloc
                mload(_calldata), // inlen
                0, // outloc
                0 // outlen
                )
            // limit our copy to 256 bytes
                _toCopy := returndatasize()
                if gt(_toCopy, _maxCopy) {
                    _toCopy := _maxCopy
                }
            // Store the length of the copied bytes
                mstore(_returnData, _toCopy)
            // copy the bytes from returndata[0:_toCopy]
                returndatacopy(add(_returnData, 0x20), 0, _toCopy)
            }
            return (_success, _returnData);
        }
        /// @notice Use when you _really_ really _really_ don't trust the called
        /// contract. This prevents the called contract from causing reversion of
        /// the caller in as many ways as we can.
        /// @dev The main difference between this and a solidity low-level call is
        /// that we limit the number of bytes that the callee can cause to be
        /// copied to caller memory. This prevents stupid things like malicious
        /// contracts returning 10,000,000 bytes causing a local OOG when copying
        /// to memory.
        /// @param _target The address to call
        /// @param _gas The amount of gas to forward to the remote contract
        /// @param _maxCopy The maximum number of bytes of returndata to copy
        /// to memory.
        /// @param _calldata The data to send to the remote contract
        /// @return success and returndata, as `.call()`. Returndata is capped to
        /// `_maxCopy` bytes.
        function excessivelySafeStaticCall(
            address _target,
            uint256 _gas,
            uint16 _maxCopy,
            bytes memory _calldata
        ) internal view returns (bool, bytes memory) {
            // set up for assembly call
            uint256 _toCopy;
            bool _success;
            bytes memory _returnData = new bytes(_maxCopy);
            // dispatch message to recipient
            // by assembly calling "handle" function
            // we call via assembly to avoid memcopying a very large returndata
            // returned by a malicious contract
            assembly {
                _success := staticcall(
                _gas, // gas
                _target, // recipient
                add(_calldata, 0x20), // inloc
                mload(_calldata), // inlen
                0, // outloc
                0 // outlen
                )
            // limit our copy to 256 bytes
                _toCopy := returndatasize()
                if gt(_toCopy, _maxCopy) {
                    _toCopy := _maxCopy
                }
            // Store the length of the copied bytes
                mstore(_returnData, _toCopy)
            // copy the bytes from returndata[0:_toCopy]
                returndatacopy(add(_returnData, 0x20), 0, _toCopy)
            }
            return (_success, _returnData);
        }
        /**
         * @notice Swaps function selectors in encoded contract calls
         * @dev Allows reuse of encoded calldata for functions with identical
         * argument types but different names. It simply swaps out the first 4 bytes
         * for the new selector. This function modifies memory in place, and should
         * only be used with caution.
         * @param _newSelector The new 4-byte selector
         * @param _buf The encoded contract args
         */
        function swapSelector(bytes4 _newSelector, bytes memory _buf)
        internal
        pure
        {
            require(_buf.length >= 4);
            uint256 _mask = LOW_28_MASK;
            assembly {
            // load the first word of
                let _word := mload(add(_buf, 0x20))
            // mask out the top 4 bytes
            // /x
                _word := and(_word, _mask)
                _word := or(_newSelector, _word)
                mstore(add(_buf, 0x20), _word)
            }
        }
    }