ETH Price: $3,736.96 (-6.93%)

Transaction Decoder

Block:
23565189 at Oct-13-2025 12:21:59 AM +UTC
Transaction Fee:
0.000046633745533375 ETH $0.17
Gas Used:
261,625 Gas / 0.178246519 Gwei

Emitted Events:

167 TransparentUpgradeableProxy.0xffb0cae73c1d6a79c81bdaa7de126a1746c06fdd17fa29bf907baf7bfa8ecaf5( 0xffb0cae73c1d6a79c81bdaa7de126a1746c06fdd17fa29bf907baf7bfa8ecaf5, 000000000000000000000000000000000000000000000000000000000000389a, 00000000000000000000000096febc813043260f5bd18da0293a0b7ac067b128, 000000000000000000000000ee8c39e57c23f4024525d21e5ad0534040b8f901, 0000000000000000000000000000000000000000000000000000000000000001 )
168 ERC1967Proxy.0x50723cfacd8baeb7b10b90b8d0e2100b5f812937f08c063e5a2c1d59fb003e28( 0x50723cfacd8baeb7b10b90b8d0e2100b5f812937f08c063e5a2c1d59fb003e28, 0x0000000000000000000000000000000000000000000000000000000000000b86, 0x000000000000000000000000000000000000000000000000000000000000389a, 3836313200000000000000000000000000000000000000000000000000000000, 00000000000000000000000096febc813043260f5bd18da0293a0b7ac067b128, 000000000000000000000000a0b86991c6218b36c1d19d4a2e9eb0ce3606eb48, 00000000000000000000000000000000000000000000000000000000127a3980, 000000000000000000000000000000000000000000000000000000006acd799b, 0000000000000000000000000000000000000000000000000000000000000001, 0000000000000000000000000000000000000000000000000000000000000001 )

Account State Difference:

  Address   Before After State Difference Code
0x1eCdB32e...a2d0c6603
(Whales Market: Markets)
(Fee Recipient: 0x52f4...536)
4.091789105986671267 Eth4.091791722236671267 Eth0.00000261625
0x96FEBC81...aC067b128
0.002423310510072002 Eth
Nonce: 341
0.002376676764538627 Eth
Nonce: 342
0.000046633745533375
0xee8c39e5...040B8f901

Execution Trace

ERC1967Proxy.3f442a42( )
  • 0x4225c565f8976566c990d3c1ff4ad43886ddf6c6.3f442a42( )
    • TransparentUpgradeableProxy.a85c38ef( )
      • 0x6eb877bf8953ceb50cd43b2e2006f781d02cc8ed.a85c38ef( )
      • TransparentUpgradeableProxy.8a72ea6a( )
        • 0x6eb877bf8953ceb50cd43b2e2006f781d02cc8ed.8a72ea6a( )
        • FiatTokenProxy.70a08231( )
          • FiatTokenV2_2.balanceOf( account=0xee8c39e57C23f4024525D21E5Ad0534040B8f901 ) => ( 0 )
          • TransparentUpgradeableProxy.3b6e750f( )
            • 0x6eb877bf8953ceb50cd43b2e2006f781d02cc8ed.3b6e750f( )
            • TransparentUpgradeableProxy.32a16f4e( )
              • 0x6eb877bf8953ceb50cd43b2e2006f781d02cc8ed.32a16f4e( )
              • TransparentUpgradeableProxy.904194a3( )
                • 0x6eb877bf8953ceb50cd43b2e2006f781d02cc8ed.904194a3( )
                • TransparentUpgradeableProxy.012fe806( )
                  • 0x6eb877bf8953ceb50cd43b2e2006f781d02cc8ed.012fe806( )
                    • Null: 0x000...001.ba197188( )
                      File 1 of 4: ERC1967Proxy
                      // SPDX-License-Identifier: MIT
                      // OpenZeppelin Contracts (last updated v4.7.0) (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 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);
                          }
                      }
                      // SPDX-License-Identifier: MIT
                      // OpenZeppelin Contracts (last updated v4.5.0) (interfaces/draft-IERC1822.sol)
                      pragma solidity ^0.8.0;
                      /**
                       * @dev ERC1822: Universal Upgradeable Proxy Standard (UUPS) documents a method for upgradeability through a simplified
                       * proxy whose upgrades are fully controlled by the current implementation.
                       */
                      interface IERC1822Proxiable {
                          /**
                           * @dev Returns the storage slot that the proxiable contract assumes is being used to store the implementation
                           * address.
                           *
                           * IMPORTANT: A proxy pointing at a proxiable contract should not be considered proxiable itself, because this risks
                           * bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this
                           * function revert if invoked through a proxy.
                           */
                          function proxiableUUID() external view returns (bytes32);
                      }
                      // SPDX-License-Identifier: MIT
                      // OpenZeppelin Contracts (last updated v4.8.3) (interfaces/IERC1967.sol)
                      pragma solidity ^0.8.0;
                      /**
                       * @dev ERC-1967: Proxy Storage Slots. This interface contains the events defined in the ERC.
                       *
                       * _Available since v4.9._
                       */
                      interface IERC1967 {
                          /**
                           * @dev Emitted when the implementation is upgraded.
                           */
                          event Upgraded(address indexed implementation);
                          /**
                           * @dev Emitted when the admin account has changed.
                           */
                          event AdminChanged(address previousAdmin, address newAdmin);
                          /**
                           * @dev Emitted when the beacon is changed.
                           */
                          event BeaconUpgraded(address indexed beacon);
                      }
                      // SPDX-License-Identifier: MIT
                      // OpenZeppelin Contracts (last updated v4.7.0) (proxy/beacon/BeaconProxy.sol)
                      pragma solidity ^0.8.0;
                      import "./IBeacon.sol";
                      import "../Proxy.sol";
                      import "../ERC1967/ERC1967Upgrade.sol";
                      /**
                       * @dev This contract implements a proxy that gets the implementation address for each call from an {UpgradeableBeacon}.
                       *
                       * The beacon address is stored in storage slot `uint256(keccak256('eip1967.proxy.beacon')) - 1`, so that it doesn't
                       * conflict with the storage layout of the implementation behind the proxy.
                       *
                       * _Available since v3.4._
                       */
                      contract BeaconProxy is Proxy, ERC1967Upgrade {
                          /**
                           * @dev Initializes the proxy with `beacon`.
                           *
                           * If `data` is nonempty, it's used as data in a delegate call to the implementation returned by the beacon. This
                           * will typically be an encoded function call, and allows initializing the storage of the proxy like a Solidity
                           * constructor.
                           *
                           * Requirements:
                           *
                           * - `beacon` must be a contract with the interface {IBeacon}.
                           */
                          constructor(address beacon, bytes memory data) payable {
                              _upgradeBeaconToAndCall(beacon, data, false);
                          }
                          /**
                           * @dev Returns the current beacon address.
                           */
                          function _beacon() internal view virtual returns (address) {
                              return _getBeacon();
                          }
                          /**
                           * @dev Returns the current implementation address of the associated beacon.
                           */
                          function _implementation() internal view virtual override returns (address) {
                              return IBeacon(_getBeacon()).implementation();
                          }
                          /**
                           * @dev Changes the proxy to use a new beacon. Deprecated: see {_upgradeBeaconToAndCall}.
                           *
                           * If `data` is nonempty, it's used as data in a delegate call to the implementation returned by the beacon.
                           *
                           * Requirements:
                           *
                           * - `beacon` must be a contract.
                           * - The implementation returned by `beacon` must be a contract.
                           */
                          function _setBeacon(address beacon, bytes memory data) internal virtual {
                              _upgradeBeaconToAndCall(beacon, data, false);
                          }
                      }
                      // SPDX-License-Identifier: MIT
                      // OpenZeppelin Contracts v4.4.1 (proxy/beacon/IBeacon.sol)
                      pragma solidity ^0.8.0;
                      /**
                       * @dev This is the interface that {BeaconProxy} expects of its beacon.
                       */
                      interface IBeacon {
                          /**
                           * @dev Must return an address that can be used as a delegate call target.
                           *
                           * {BeaconProxy} will check that this address is a contract.
                           */
                          function implementation() external view returns (address);
                      }
                      // SPDX-License-Identifier: MIT
                      // OpenZeppelin Contracts v4.4.1 (proxy/beacon/UpgradeableBeacon.sol)
                      pragma solidity ^0.8.0;
                      import "./IBeacon.sol";
                      import "../../access/Ownable.sol";
                      import "../../utils/Address.sol";
                      /**
                       * @dev This contract is used in conjunction with one or more instances of {BeaconProxy} to determine their
                       * implementation contract, which is where they will delegate all function calls.
                       *
                       * An owner is able to change the implementation the beacon points to, thus upgrading the proxies that use this beacon.
                       */
                      contract UpgradeableBeacon is IBeacon, Ownable {
                          address private _implementation;
                          /**
                           * @dev Emitted when the implementation returned by the beacon is changed.
                           */
                          event Upgraded(address indexed implementation);
                          /**
                           * @dev Sets the address of the initial implementation, and the deployer account as the owner who can upgrade the
                           * beacon.
                           */
                          constructor(address implementation_) {
                              _setImplementation(implementation_);
                          }
                          /**
                           * @dev Returns the current implementation address.
                           */
                          function implementation() public view virtual override returns (address) {
                              return _implementation;
                          }
                          /**
                           * @dev Upgrades the beacon to a new implementation.
                           *
                           * Emits an {Upgraded} event.
                           *
                           * Requirements:
                           *
                           * - msg.sender must be the owner of the contract.
                           * - `newImplementation` must be a contract.
                           */
                          function upgradeTo(address newImplementation) public virtual onlyOwner {
                              _setImplementation(newImplementation);
                              emit Upgraded(newImplementation);
                          }
                          /**
                           * @dev Sets the implementation contract address for this beacon
                           *
                           * Requirements:
                           *
                           * - `newImplementation` must be a contract.
                           */
                          function _setImplementation(address newImplementation) private {
                              require(Address.isContract(newImplementation), "UpgradeableBeacon: implementation is not a contract");
                              _implementation = newImplementation;
                          }
                      }
                      // SPDX-License-Identifier: MIT
                      // OpenZeppelin Contracts (last updated v4.7.0) (proxy/ERC1967/ERC1967Proxy.sol)
                      pragma solidity ^0.8.0;
                      import "../Proxy.sol";
                      import "./ERC1967Upgrade.sol";
                      /**
                       * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
                       * implementation address that can be changed. This address is stored in storage in the location specified by
                       * https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the
                       * implementation behind the proxy.
                       */
                      contract ERC1967Proxy is Proxy, ERC1967Upgrade {
                          /**
                           * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`.
                           *
                           * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded
                           * function call, and allows initializing the storage of the proxy like a Solidity constructor.
                           */
                          constructor(address _logic, bytes memory _data) payable {
                              _upgradeToAndCall(_logic, _data, false);
                          }
                          /**
                           * @dev Returns the current implementation address.
                           */
                          function _implementation() internal view virtual override returns (address impl) {
                              return ERC1967Upgrade._getImplementation();
                          }
                      }
                      // SPDX-License-Identifier: MIT
                      // OpenZeppelin Contracts (last updated v4.8.3) (proxy/ERC1967/ERC1967Upgrade.sol)
                      pragma solidity ^0.8.2;
                      import "../beacon/IBeacon.sol";
                      import "../../interfaces/IERC1967.sol";
                      import "../../interfaces/draft-IERC1822.sol";
                      import "../../utils/Address.sol";
                      import "../../utils/StorageSlot.sol";
                      /**
                       * @dev This abstract contract provides getters and event emitting update functions for
                       * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
                       *
                       * _Available since v4.1._
                       *
                       * @custom:oz-upgrades-unsafe-allow delegatecall
                       */
                      abstract contract ERC1967Upgrade is IERC1967 {
                          // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
                          bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;
                          /**
                           * @dev Storage slot with the address of the current implementation.
                           * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
                           * validated in the constructor.
                           */
                          bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
                          /**
                           * @dev Returns the current implementation address.
                           */
                          function _getImplementation() internal view returns (address) {
                              return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
                          }
                          /**
                           * @dev Stores a new address in the EIP1967 implementation slot.
                           */
                          function _setImplementation(address newImplementation) private {
                              require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
                              StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
                          }
                          /**
                           * @dev Perform implementation upgrade
                           *
                           * Emits an {Upgraded} event.
                           */
                          function _upgradeTo(address newImplementation) internal {
                              _setImplementation(newImplementation);
                              emit Upgraded(newImplementation);
                          }
                          /**
                           * @dev Perform implementation upgrade with additional setup call.
                           *
                           * Emits an {Upgraded} event.
                           */
                          function _upgradeToAndCall(
                              address newImplementation,
                              bytes memory data,
                              bool forceCall
                          ) internal {
                              _upgradeTo(newImplementation);
                              if (data.length > 0 || forceCall) {
                                  Address.functionDelegateCall(newImplementation, data);
                              }
                          }
                          /**
                           * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
                           *
                           * Emits an {Upgraded} event.
                           */
                          function _upgradeToAndCallUUPS(
                              address newImplementation,
                              bytes memory data,
                              bool forceCall
                          ) internal {
                              // Upgrades from old implementations will perform a rollback test. This test requires the new
                              // implementation to upgrade back to the old, non-ERC1822 compliant, implementation. Removing
                              // this special case will break upgrade paths from old UUPS implementation to new ones.
                              if (StorageSlot.getBooleanSlot(_ROLLBACK_SLOT).value) {
                                  _setImplementation(newImplementation);
                              } else {
                                  try IERC1822Proxiable(newImplementation).proxiableUUID() returns (bytes32 slot) {
                                      require(slot == _IMPLEMENTATION_SLOT, "ERC1967Upgrade: unsupported proxiableUUID");
                                  } catch {
                                      revert("ERC1967Upgrade: new implementation is not UUPS");
                                  }
                                  _upgradeToAndCall(newImplementation, data, forceCall);
                              }
                          }
                          /**
                           * @dev Storage slot with the admin of the contract.
                           * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
                           * validated in the constructor.
                           */
                          bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
                          /**
                           * @dev Returns the current admin.
                           */
                          function _getAdmin() internal view returns (address) {
                              return StorageSlot.getAddressSlot(_ADMIN_SLOT).value;
                          }
                          /**
                           * @dev Stores a new address in the EIP1967 admin slot.
                           */
                          function _setAdmin(address newAdmin) private {
                              require(newAdmin != address(0), "ERC1967: new admin is the zero address");
                              StorageSlot.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
                          }
                          /**
                           * @dev Changes the admin of the proxy.
                           *
                           * Emits an {AdminChanged} event.
                           */
                          function _changeAdmin(address newAdmin) internal {
                              emit AdminChanged(_getAdmin(), newAdmin);
                              _setAdmin(newAdmin);
                          }
                          /**
                           * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
                           * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
                           */
                          bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
                          /**
                           * @dev Returns the current beacon.
                           */
                          function _getBeacon() internal view returns (address) {
                              return StorageSlot.getAddressSlot(_BEACON_SLOT).value;
                          }
                          /**
                           * @dev Stores a new beacon in the EIP1967 beacon slot.
                           */
                          function _setBeacon(address newBeacon) private {
                              require(Address.isContract(newBeacon), "ERC1967: new beacon is not a contract");
                              require(
                                  Address.isContract(IBeacon(newBeacon).implementation()),
                                  "ERC1967: beacon implementation is not a contract"
                              );
                              StorageSlot.getAddressSlot(_BEACON_SLOT).value = newBeacon;
                          }
                          /**
                           * @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
                           * not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
                           *
                           * Emits a {BeaconUpgraded} event.
                           */
                          function _upgradeBeaconToAndCall(
                              address newBeacon,
                              bytes memory data,
                              bool forceCall
                          ) internal {
                              _setBeacon(newBeacon);
                              emit BeaconUpgraded(newBeacon);
                              if (data.length > 0 || forceCall) {
                                  Address.functionDelegateCall(IBeacon(newBeacon).implementation(), data);
                              }
                          }
                      }
                      // SPDX-License-Identifier: MIT
                      // OpenZeppelin Contracts (last updated v4.6.0) (proxy/Proxy.sol)
                      pragma solidity ^0.8.0;
                      /**
                       * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
                       * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
                       * be specified by overriding the virtual {_implementation} function.
                       *
                       * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
                       * different contract through the {_delegate} function.
                       *
                       * The success and return data of the delegated call will be returned back to the caller of the proxy.
                       */
                      abstract contract Proxy {
                          /**
                           * @dev Delegates the current call to `implementation`.
                           *
                           * This function does not return to its internal call site, it will return directly to the external caller.
                           */
                          function _delegate(address implementation) internal virtual {
                              assembly {
                                  // Copy msg.data. We take full control of memory in this inline assembly
                                  // block because it will not return to Solidity code. We overwrite the
                                  // Solidity scratch pad at memory position 0.
                                  calldatacopy(0, 0, calldatasize())
                                  // Call the implementation.
                                  // out and outsize are 0 because we don't know the size yet.
                                  let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)
                                  // Copy the returned data.
                                  returndatacopy(0, 0, returndatasize())
                                  switch result
                                  // delegatecall returns 0 on error.
                                  case 0 {
                                      revert(0, returndatasize())
                                  }
                                  default {
                                      return(0, returndatasize())
                                  }
                              }
                          }
                          /**
                           * @dev This is a virtual function that should be overridden so it returns the address to which the fallback function
                           * and {_fallback} should delegate.
                           */
                          function _implementation() internal view virtual returns (address);
                          /**
                           * @dev Delegates the current call to the address returned by `_implementation()`.
                           *
                           * This function does not return to its internal call site, it will return directly to the external caller.
                           */
                          function _fallback() internal virtual {
                              _beforeFallback();
                              _delegate(_implementation());
                          }
                          /**
                           * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
                           * function in the contract matches the call data.
                           */
                          fallback() external payable virtual {
                              _fallback();
                          }
                          /**
                           * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
                           * is empty.
                           */
                          receive() external payable virtual {
                              _fallback();
                          }
                          /**
                           * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
                           * call, or as part of the Solidity `fallback` or `receive` functions.
                           *
                           * If overridden should call `super._beforeFallback()`.
                           */
                          function _beforeFallback() internal virtual {}
                      }
                      // SPDX-License-Identifier: MIT
                      // OpenZeppelin Contracts (last updated v4.8.3) (proxy/transparent/ProxyAdmin.sol)
                      pragma solidity ^0.8.0;
                      import "./TransparentUpgradeableProxy.sol";
                      import "../../access/Ownable.sol";
                      /**
                       * @dev This is an auxiliary contract meant to be assigned as the admin of a {TransparentUpgradeableProxy}. For an
                       * explanation of why you would want to use this see the documentation for {TransparentUpgradeableProxy}.
                       */
                      contract ProxyAdmin is Ownable {
                          /**
                           * @dev Returns the current implementation of `proxy`.
                           *
                           * Requirements:
                           *
                           * - This contract must be the admin of `proxy`.
                           */
                          function getProxyImplementation(ITransparentUpgradeableProxy proxy) public view virtual returns (address) {
                              // We need to manually run the static call since the getter cannot be flagged as view
                              // bytes4(keccak256("implementation()")) == 0x5c60da1b
                              (bool success, bytes memory returndata) = address(proxy).staticcall(hex"5c60da1b");
                              require(success);
                              return abi.decode(returndata, (address));
                          }
                          /**
                           * @dev Returns the current admin of `proxy`.
                           *
                           * Requirements:
                           *
                           * - This contract must be the admin of `proxy`.
                           */
                          function getProxyAdmin(ITransparentUpgradeableProxy proxy) public view virtual returns (address) {
                              // We need to manually run the static call since the getter cannot be flagged as view
                              // bytes4(keccak256("admin()")) == 0xf851a440
                              (bool success, bytes memory returndata) = address(proxy).staticcall(hex"f851a440");
                              require(success);
                              return abi.decode(returndata, (address));
                          }
                          /**
                           * @dev Changes the admin of `proxy` to `newAdmin`.
                           *
                           * Requirements:
                           *
                           * - This contract must be the current admin of `proxy`.
                           */
                          function changeProxyAdmin(ITransparentUpgradeableProxy proxy, address newAdmin) public virtual onlyOwner {
                              proxy.changeAdmin(newAdmin);
                          }
                          /**
                           * @dev Upgrades `proxy` to `implementation`. See {TransparentUpgradeableProxy-upgradeTo}.
                           *
                           * Requirements:
                           *
                           * - This contract must be the admin of `proxy`.
                           */
                          function upgrade(ITransparentUpgradeableProxy proxy, address implementation) public virtual onlyOwner {
                              proxy.upgradeTo(implementation);
                          }
                          /**
                           * @dev Upgrades `proxy` to `implementation` and calls a function on the new implementation. See
                           * {TransparentUpgradeableProxy-upgradeToAndCall}.
                           *
                           * Requirements:
                           *
                           * - This contract must be the admin of `proxy`.
                           */
                          function upgradeAndCall(
                              ITransparentUpgradeableProxy proxy,
                              address implementation,
                              bytes memory data
                          ) public payable virtual onlyOwner {
                              proxy.upgradeToAndCall{value: msg.value}(implementation, data);
                          }
                      }
                      // SPDX-License-Identifier: MIT
                      // OpenZeppelin Contracts (last updated v4.8.3) (proxy/transparent/TransparentUpgradeableProxy.sol)
                      pragma solidity ^0.8.0;
                      import "../ERC1967/ERC1967Proxy.sol";
                      /**
                       * @dev Interface for {TransparentUpgradeableProxy}. In order to implement transparency, {TransparentUpgradeableProxy}
                       * does not implement this interface directly, and some of its functions are implemented by an internal dispatch
                       * mechanism. The compiler is unaware that these functions are implemented by {TransparentUpgradeableProxy} and will not
                       * include them in the ABI so this interface must be used to interact with it.
                       */
                      interface ITransparentUpgradeableProxy is IERC1967 {
                          function admin() external view returns (address);
                          function implementation() external view returns (address);
                          function changeAdmin(address) external;
                          function upgradeTo(address) external;
                          function upgradeToAndCall(address, bytes memory) external payable;
                      }
                      /**
                       * @dev This contract implements a proxy that is upgradeable by an admin.
                       *
                       * To avoid https://medium.com/nomic-labs-blog/malicious-backdoors-in-ethereum-proxies-62629adf3357[proxy selector
                       * clashing], which can potentially be used in an attack, this contract uses the
                       * https://blog.openzeppelin.com/the-transparent-proxy-pattern/[transparent proxy pattern]. This pattern implies two
                       * things that go hand in hand:
                       *
                       * 1. If any account other than the admin calls the proxy, the call will be forwarded to the implementation, even if
                       * that call matches one of the admin functions exposed by the proxy itself.
                       * 2. If the admin calls the proxy, it can access the admin functions, but its calls will never be forwarded to the
                       * implementation. If the admin tries to call a function on the implementation it will fail with an error that says
                       * "admin cannot fallback to proxy target".
                       *
                       * These properties mean that the admin account can only be used for admin actions like upgrading the proxy or changing
                       * the admin, so it's best if it's a dedicated account that is not used for anything else. This will avoid headaches due
                       * to sudden errors when trying to call a function from the proxy implementation.
                       *
                       * Our recommendation is for the dedicated account to be an instance of the {ProxyAdmin} contract. If set up this way,
                       * you should think of the `ProxyAdmin` instance as the real administrative interface of your proxy.
                       *
                       * NOTE: The real interface of this proxy is that defined in `ITransparentUpgradeableProxy`. This contract does not
                       * inherit from that interface, and instead the admin functions are implicitly implemented using a custom dispatch
                       * mechanism in `_fallback`. Consequently, the compiler will not produce an ABI for this contract. This is necessary to
                       * fully implement transparency without decoding reverts caused by selector clashes between the proxy and the
                       * implementation.
                       *
                       * WARNING: It is not recommended to extend this contract to add additional external functions. If you do so, the compiler
                       * will not check that there are no selector conflicts, due to the note above. A selector clash between any new function
                       * and the functions declared in {ITransparentUpgradeableProxy} will be resolved in favor of the new one. This could
                       * render the admin operations inaccessible, which could prevent upgradeability. Transparency may also be compromised.
                       */
                      contract TransparentUpgradeableProxy is ERC1967Proxy {
                          /**
                           * @dev Initializes an upgradeable proxy managed by `_admin`, backed by the implementation at `_logic`, and
                           * optionally initialized with `_data` as explained in {ERC1967Proxy-constructor}.
                           */
                          constructor(
                              address _logic,
                              address admin_,
                              bytes memory _data
                          ) payable ERC1967Proxy(_logic, _data) {
                              _changeAdmin(admin_);
                          }
                          /**
                           * @dev Modifier used internally that will delegate the call to the implementation unless the sender is the admin.
                           *
                           * CAUTION: This modifier is deprecated, as it could cause issues if the modified function has arguments, and the
                           * implementation provides a function with the same selector.
                           */
                          modifier ifAdmin() {
                              if (msg.sender == _getAdmin()) {
                                  _;
                              } else {
                                  _fallback();
                              }
                          }
                          /**
                           * @dev If caller is the admin process the call internally, otherwise transparently fallback to the proxy behavior
                           */
                          function _fallback() internal virtual override {
                              if (msg.sender == _getAdmin()) {
                                  bytes memory ret;
                                  bytes4 selector = msg.sig;
                                  if (selector == ITransparentUpgradeableProxy.upgradeTo.selector) {
                                      ret = _dispatchUpgradeTo();
                                  } else if (selector == ITransparentUpgradeableProxy.upgradeToAndCall.selector) {
                                      ret = _dispatchUpgradeToAndCall();
                                  } else if (selector == ITransparentUpgradeableProxy.changeAdmin.selector) {
                                      ret = _dispatchChangeAdmin();
                                  } else if (selector == ITransparentUpgradeableProxy.admin.selector) {
                                      ret = _dispatchAdmin();
                                  } else if (selector == ITransparentUpgradeableProxy.implementation.selector) {
                                      ret = _dispatchImplementation();
                                  } else {
                                      revert("TransparentUpgradeableProxy: admin cannot fallback to proxy target");
                                  }
                                  assembly {
                                      return(add(ret, 0x20), mload(ret))
                                  }
                              } else {
                                  super._fallback();
                              }
                          }
                          /**
                           * @dev Returns the current admin.
                           *
                           * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
                           * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
                           * `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
                           */
                          function _dispatchAdmin() private returns (bytes memory) {
                              _requireZeroValue();
                              address admin = _getAdmin();
                              return abi.encode(admin);
                          }
                          /**
                           * @dev Returns the current implementation.
                           *
                           * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
                           * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
                           * `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
                           */
                          function _dispatchImplementation() private returns (bytes memory) {
                              _requireZeroValue();
                              address implementation = _implementation();
                              return abi.encode(implementation);
                          }
                          /**
                           * @dev Changes the admin of the proxy.
                           *
                           * Emits an {AdminChanged} event.
                           */
                          function _dispatchChangeAdmin() private returns (bytes memory) {
                              _requireZeroValue();
                              address newAdmin = abi.decode(msg.data[4:], (address));
                              _changeAdmin(newAdmin);
                              return "";
                          }
                          /**
                           * @dev Upgrade the implementation of the proxy.
                           */
                          function _dispatchUpgradeTo() private returns (bytes memory) {
                              _requireZeroValue();
                              address newImplementation = abi.decode(msg.data[4:], (address));
                              _upgradeToAndCall(newImplementation, bytes(""), false);
                              return "";
                          }
                          /**
                           * @dev Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
                           * by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
                           * proxied contract.
                           */
                          function _dispatchUpgradeToAndCall() private returns (bytes memory) {
                              (address newImplementation, bytes memory data) = abi.decode(msg.data[4:], (address, bytes));
                              _upgradeToAndCall(newImplementation, data, true);
                              return "";
                          }
                          /**
                           * @dev Returns the current admin.
                           */
                          function _admin() internal view virtual returns (address) {
                              return _getAdmin();
                          }
                          /**
                           * @dev To keep this contract fully transparent, all `ifAdmin` functions must be payable. This helper is here to
                           * emulate some proxy functions being non-payable while still allowing value to pass through.
                           */
                          function _requireZeroValue() private {
                              require(msg.value == 0);
                          }
                      }
                      // SPDX-License-Identifier: MIT
                      // OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol)
                      pragma solidity ^0.8.1;
                      /**
                       * @dev Collection of functions related to the address type
                       */
                      library Address {
                          /**
                           * @dev Returns true if `account` is a contract.
                           *
                           * [IMPORTANT]
                           * ====
                           * It is unsafe to assume that an address for which this function returns
                           * false is an externally-owned account (EOA) and not a contract.
                           *
                           * Among others, `isContract` will return false for the following
                           * types of addresses:
                           *
                           *  - an externally-owned account
                           *  - a contract in construction
                           *  - an address where a contract will be created
                           *  - an address where a contract lived, but was destroyed
                           * ====
                           *
                           * [IMPORTANT]
                           * ====
                           * You shouldn't rely on `isContract` to protect against flash loan attacks!
                           *
                           * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
                           * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
                           * constructor.
                           * ====
                           */
                          function isContract(address account) internal view returns (bool) {
                              // This method relies on extcodesize/address.code.length, which returns 0
                              // for contracts in construction, since the code is only stored at the end
                              // of the constructor execution.
                              return account.code.length > 0;
                          }
                          /**
                           * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
                           * `recipient`, forwarding all available gas and reverting on errors.
                           *
                           * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
                           * of certain opcodes, possibly making contracts go over the 2300 gas limit
                           * imposed by `transfer`, making them unable to receive funds via
                           * `transfer`. {sendValue} removes this limitation.
                           *
                           * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
                           *
                           * IMPORTANT: because control is transferred to `recipient`, care must be
                           * taken to not create reentrancy vulnerabilities. Consider using
                           * {ReentrancyGuard} or the
                           * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
                           */
                          function sendValue(address payable recipient, uint256 amount) internal {
                              require(address(this).balance >= amount, "Address: insufficient balance");
                              (bool success, ) = recipient.call{value: amount}("");
                              require(success, "Address: unable to send value, recipient may have reverted");
                          }
                          /**
                           * @dev Performs a Solidity function call using a low level `call`. A
                           * plain `call` is an unsafe replacement for a function call: use this
                           * function instead.
                           *
                           * If `target` reverts with a revert reason, it is bubbled up by this
                           * function (like regular Solidity function calls).
                           *
                           * Returns the raw returned data. To convert to the expected return value,
                           * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
                           *
                           * Requirements:
                           *
                           * - `target` must be a contract.
                           * - calling `target` with `data` must not revert.
                           *
                           * _Available since v3.1._
                           */
                          function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                              return 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 v4.7.0) (utils/StorageSlot.sol)
                      pragma solidity ^0.8.0;
                      /**
                       * @dev Library for reading and writing primitive types to specific storage slots.
                       *
                       * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
                       * This library helps with reading and writing to such slots without the need for inline assembly.
                       *
                       * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
                       *
                       * Example usage to set ERC1967 implementation slot:
                       * ```
                       * contract ERC1967 {
                       *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
                       *
                       *     function _getImplementation() internal view returns (address) {
                       *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
                       *     }
                       *
                       *     function _setImplementation(address newImplementation) internal {
                       *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
                       *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
                       *     }
                       * }
                       * ```
                       *
                       * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
                       */
                      library StorageSlot {
                          struct AddressSlot {
                              address value;
                          }
                          struct BooleanSlot {
                              bool value;
                          }
                          struct Bytes32Slot {
                              bytes32 value;
                          }
                          struct Uint256Slot {
                              uint256 value;
                          }
                          /**
                           * @dev Returns an `AddressSlot` with member `value` located at `slot`.
                           */
                          function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
                              /// @solidity memory-safe-assembly
                              assembly {
                                  r.slot := slot
                              }
                          }
                          /**
                           * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
                           */
                          function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
                              /// @solidity memory-safe-assembly
                              assembly {
                                  r.slot := slot
                              }
                          }
                          /**
                           * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
                           */
                          function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
                              /// @solidity memory-safe-assembly
                              assembly {
                                  r.slot := slot
                              }
                          }
                          /**
                           * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
                           */
                          function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
                              /// @solidity memory-safe-assembly
                              assembly {
                                  r.slot := slot
                              }
                          }
                      }
                      

                      File 2 of 4: TransparentUpgradeableProxy
                      // SPDX-License-Identifier: MIT
                      // OpenZeppelin Contracts (last updated v4.7.0) (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 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);
                          }
                      }
                      // SPDX-License-Identifier: MIT
                      // OpenZeppelin Contracts (last updated v4.5.0) (interfaces/draft-IERC1822.sol)
                      pragma solidity ^0.8.0;
                      /**
                       * @dev ERC1822: Universal Upgradeable Proxy Standard (UUPS) documents a method for upgradeability through a simplified
                       * proxy whose upgrades are fully controlled by the current implementation.
                       */
                      interface IERC1822Proxiable {
                          /**
                           * @dev Returns the storage slot that the proxiable contract assumes is being used to store the implementation
                           * address.
                           *
                           * IMPORTANT: A proxy pointing at a proxiable contract should not be considered proxiable itself, because this risks
                           * bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this
                           * function revert if invoked through a proxy.
                           */
                          function proxiableUUID() external view returns (bytes32);
                      }
                      // SPDX-License-Identifier: MIT
                      // OpenZeppelin Contracts (last updated v4.8.3) (interfaces/IERC1967.sol)
                      pragma solidity ^0.8.0;
                      /**
                       * @dev ERC-1967: Proxy Storage Slots. This interface contains the events defined in the ERC.
                       *
                       * _Available since v4.9._
                       */
                      interface IERC1967 {
                          /**
                           * @dev Emitted when the implementation is upgraded.
                           */
                          event Upgraded(address indexed implementation);
                          /**
                           * @dev Emitted when the admin account has changed.
                           */
                          event AdminChanged(address previousAdmin, address newAdmin);
                          /**
                           * @dev Emitted when the beacon is changed.
                           */
                          event BeaconUpgraded(address indexed beacon);
                      }
                      // SPDX-License-Identifier: MIT
                      // OpenZeppelin Contracts (last updated v4.7.0) (proxy/beacon/BeaconProxy.sol)
                      pragma solidity ^0.8.0;
                      import "./IBeacon.sol";
                      import "../Proxy.sol";
                      import "../ERC1967/ERC1967Upgrade.sol";
                      /**
                       * @dev This contract implements a proxy that gets the implementation address for each call from an {UpgradeableBeacon}.
                       *
                       * The beacon address is stored in storage slot `uint256(keccak256('eip1967.proxy.beacon')) - 1`, so that it doesn't
                       * conflict with the storage layout of the implementation behind the proxy.
                       *
                       * _Available since v3.4._
                       */
                      contract BeaconProxy is Proxy, ERC1967Upgrade {
                          /**
                           * @dev Initializes the proxy with `beacon`.
                           *
                           * If `data` is nonempty, it's used as data in a delegate call to the implementation returned by the beacon. This
                           * will typically be an encoded function call, and allows initializing the storage of the proxy like a Solidity
                           * constructor.
                           *
                           * Requirements:
                           *
                           * - `beacon` must be a contract with the interface {IBeacon}.
                           */
                          constructor(address beacon, bytes memory data) payable {
                              _upgradeBeaconToAndCall(beacon, data, false);
                          }
                          /**
                           * @dev Returns the current beacon address.
                           */
                          function _beacon() internal view virtual returns (address) {
                              return _getBeacon();
                          }
                          /**
                           * @dev Returns the current implementation address of the associated beacon.
                           */
                          function _implementation() internal view virtual override returns (address) {
                              return IBeacon(_getBeacon()).implementation();
                          }
                          /**
                           * @dev Changes the proxy to use a new beacon. Deprecated: see {_upgradeBeaconToAndCall}.
                           *
                           * If `data` is nonempty, it's used as data in a delegate call to the implementation returned by the beacon.
                           *
                           * Requirements:
                           *
                           * - `beacon` must be a contract.
                           * - The implementation returned by `beacon` must be a contract.
                           */
                          function _setBeacon(address beacon, bytes memory data) internal virtual {
                              _upgradeBeaconToAndCall(beacon, data, false);
                          }
                      }
                      // SPDX-License-Identifier: MIT
                      // OpenZeppelin Contracts v4.4.1 (proxy/beacon/IBeacon.sol)
                      pragma solidity ^0.8.0;
                      /**
                       * @dev This is the interface that {BeaconProxy} expects of its beacon.
                       */
                      interface IBeacon {
                          /**
                           * @dev Must return an address that can be used as a delegate call target.
                           *
                           * {BeaconProxy} will check that this address is a contract.
                           */
                          function implementation() external view returns (address);
                      }
                      // SPDX-License-Identifier: MIT
                      // OpenZeppelin Contracts v4.4.1 (proxy/beacon/UpgradeableBeacon.sol)
                      pragma solidity ^0.8.0;
                      import "./IBeacon.sol";
                      import "../../access/Ownable.sol";
                      import "../../utils/Address.sol";
                      /**
                       * @dev This contract is used in conjunction with one or more instances of {BeaconProxy} to determine their
                       * implementation contract, which is where they will delegate all function calls.
                       *
                       * An owner is able to change the implementation the beacon points to, thus upgrading the proxies that use this beacon.
                       */
                      contract UpgradeableBeacon is IBeacon, Ownable {
                          address private _implementation;
                          /**
                           * @dev Emitted when the implementation returned by the beacon is changed.
                           */
                          event Upgraded(address indexed implementation);
                          /**
                           * @dev Sets the address of the initial implementation, and the deployer account as the owner who can upgrade the
                           * beacon.
                           */
                          constructor(address implementation_) {
                              _setImplementation(implementation_);
                          }
                          /**
                           * @dev Returns the current implementation address.
                           */
                          function implementation() public view virtual override returns (address) {
                              return _implementation;
                          }
                          /**
                           * @dev Upgrades the beacon to a new implementation.
                           *
                           * Emits an {Upgraded} event.
                           *
                           * Requirements:
                           *
                           * - msg.sender must be the owner of the contract.
                           * - `newImplementation` must be a contract.
                           */
                          function upgradeTo(address newImplementation) public virtual onlyOwner {
                              _setImplementation(newImplementation);
                              emit Upgraded(newImplementation);
                          }
                          /**
                           * @dev Sets the implementation contract address for this beacon
                           *
                           * Requirements:
                           *
                           * - `newImplementation` must be a contract.
                           */
                          function _setImplementation(address newImplementation) private {
                              require(Address.isContract(newImplementation), "UpgradeableBeacon: implementation is not a contract");
                              _implementation = newImplementation;
                          }
                      }
                      // SPDX-License-Identifier: MIT
                      // OpenZeppelin Contracts (last updated v4.7.0) (proxy/ERC1967/ERC1967Proxy.sol)
                      pragma solidity ^0.8.0;
                      import "../Proxy.sol";
                      import "./ERC1967Upgrade.sol";
                      /**
                       * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
                       * implementation address that can be changed. This address is stored in storage in the location specified by
                       * https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the
                       * implementation behind the proxy.
                       */
                      contract ERC1967Proxy is Proxy, ERC1967Upgrade {
                          /**
                           * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`.
                           *
                           * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded
                           * function call, and allows initializing the storage of the proxy like a Solidity constructor.
                           */
                          constructor(address _logic, bytes memory _data) payable {
                              _upgradeToAndCall(_logic, _data, false);
                          }
                          /**
                           * @dev Returns the current implementation address.
                           */
                          function _implementation() internal view virtual override returns (address impl) {
                              return ERC1967Upgrade._getImplementation();
                          }
                      }
                      // SPDX-License-Identifier: MIT
                      // OpenZeppelin Contracts (last updated v4.8.3) (proxy/ERC1967/ERC1967Upgrade.sol)
                      pragma solidity ^0.8.2;
                      import "../beacon/IBeacon.sol";
                      import "../../interfaces/IERC1967.sol";
                      import "../../interfaces/draft-IERC1822.sol";
                      import "../../utils/Address.sol";
                      import "../../utils/StorageSlot.sol";
                      /**
                       * @dev This abstract contract provides getters and event emitting update functions for
                       * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
                       *
                       * _Available since v4.1._
                       *
                       * @custom:oz-upgrades-unsafe-allow delegatecall
                       */
                      abstract contract ERC1967Upgrade is IERC1967 {
                          // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
                          bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;
                          /**
                           * @dev Storage slot with the address of the current implementation.
                           * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
                           * validated in the constructor.
                           */
                          bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
                          /**
                           * @dev Returns the current implementation address.
                           */
                          function _getImplementation() internal view returns (address) {
                              return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
                          }
                          /**
                           * @dev Stores a new address in the EIP1967 implementation slot.
                           */
                          function _setImplementation(address newImplementation) private {
                              require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
                              StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
                          }
                          /**
                           * @dev Perform implementation upgrade
                           *
                           * Emits an {Upgraded} event.
                           */
                          function _upgradeTo(address newImplementation) internal {
                              _setImplementation(newImplementation);
                              emit Upgraded(newImplementation);
                          }
                          /**
                           * @dev Perform implementation upgrade with additional setup call.
                           *
                           * Emits an {Upgraded} event.
                           */
                          function _upgradeToAndCall(
                              address newImplementation,
                              bytes memory data,
                              bool forceCall
                          ) internal {
                              _upgradeTo(newImplementation);
                              if (data.length > 0 || forceCall) {
                                  Address.functionDelegateCall(newImplementation, data);
                              }
                          }
                          /**
                           * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
                           *
                           * Emits an {Upgraded} event.
                           */
                          function _upgradeToAndCallUUPS(
                              address newImplementation,
                              bytes memory data,
                              bool forceCall
                          ) internal {
                              // Upgrades from old implementations will perform a rollback test. This test requires the new
                              // implementation to upgrade back to the old, non-ERC1822 compliant, implementation. Removing
                              // this special case will break upgrade paths from old UUPS implementation to new ones.
                              if (StorageSlot.getBooleanSlot(_ROLLBACK_SLOT).value) {
                                  _setImplementation(newImplementation);
                              } else {
                                  try IERC1822Proxiable(newImplementation).proxiableUUID() returns (bytes32 slot) {
                                      require(slot == _IMPLEMENTATION_SLOT, "ERC1967Upgrade: unsupported proxiableUUID");
                                  } catch {
                                      revert("ERC1967Upgrade: new implementation is not UUPS");
                                  }
                                  _upgradeToAndCall(newImplementation, data, forceCall);
                              }
                          }
                          /**
                           * @dev Storage slot with the admin of the contract.
                           * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
                           * validated in the constructor.
                           */
                          bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
                          /**
                           * @dev Returns the current admin.
                           */
                          function _getAdmin() internal view returns (address) {
                              return StorageSlot.getAddressSlot(_ADMIN_SLOT).value;
                          }
                          /**
                           * @dev Stores a new address in the EIP1967 admin slot.
                           */
                          function _setAdmin(address newAdmin) private {
                              require(newAdmin != address(0), "ERC1967: new admin is the zero address");
                              StorageSlot.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
                          }
                          /**
                           * @dev Changes the admin of the proxy.
                           *
                           * Emits an {AdminChanged} event.
                           */
                          function _changeAdmin(address newAdmin) internal {
                              emit AdminChanged(_getAdmin(), newAdmin);
                              _setAdmin(newAdmin);
                          }
                          /**
                           * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
                           * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
                           */
                          bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
                          /**
                           * @dev Returns the current beacon.
                           */
                          function _getBeacon() internal view returns (address) {
                              return StorageSlot.getAddressSlot(_BEACON_SLOT).value;
                          }
                          /**
                           * @dev Stores a new beacon in the EIP1967 beacon slot.
                           */
                          function _setBeacon(address newBeacon) private {
                              require(Address.isContract(newBeacon), "ERC1967: new beacon is not a contract");
                              require(
                                  Address.isContract(IBeacon(newBeacon).implementation()),
                                  "ERC1967: beacon implementation is not a contract"
                              );
                              StorageSlot.getAddressSlot(_BEACON_SLOT).value = newBeacon;
                          }
                          /**
                           * @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
                           * not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
                           *
                           * Emits a {BeaconUpgraded} event.
                           */
                          function _upgradeBeaconToAndCall(
                              address newBeacon,
                              bytes memory data,
                              bool forceCall
                          ) internal {
                              _setBeacon(newBeacon);
                              emit BeaconUpgraded(newBeacon);
                              if (data.length > 0 || forceCall) {
                                  Address.functionDelegateCall(IBeacon(newBeacon).implementation(), data);
                              }
                          }
                      }
                      // SPDX-License-Identifier: MIT
                      // OpenZeppelin Contracts (last updated v4.6.0) (proxy/Proxy.sol)
                      pragma solidity ^0.8.0;
                      /**
                       * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
                       * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
                       * be specified by overriding the virtual {_implementation} function.
                       *
                       * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
                       * different contract through the {_delegate} function.
                       *
                       * The success and return data of the delegated call will be returned back to the caller of the proxy.
                       */
                      abstract contract Proxy {
                          /**
                           * @dev Delegates the current call to `implementation`.
                           *
                           * This function does not return to its internal call site, it will return directly to the external caller.
                           */
                          function _delegate(address implementation) internal virtual {
                              assembly {
                                  // Copy msg.data. We take full control of memory in this inline assembly
                                  // block because it will not return to Solidity code. We overwrite the
                                  // Solidity scratch pad at memory position 0.
                                  calldatacopy(0, 0, calldatasize())
                                  // Call the implementation.
                                  // out and outsize are 0 because we don't know the size yet.
                                  let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)
                                  // Copy the returned data.
                                  returndatacopy(0, 0, returndatasize())
                                  switch result
                                  // delegatecall returns 0 on error.
                                  case 0 {
                                      revert(0, returndatasize())
                                  }
                                  default {
                                      return(0, returndatasize())
                                  }
                              }
                          }
                          /**
                           * @dev This is a virtual function that should be overridden so it returns the address to which the fallback function
                           * and {_fallback} should delegate.
                           */
                          function _implementation() internal view virtual returns (address);
                          /**
                           * @dev Delegates the current call to the address returned by `_implementation()`.
                           *
                           * This function does not return to its internal call site, it will return directly to the external caller.
                           */
                          function _fallback() internal virtual {
                              _beforeFallback();
                              _delegate(_implementation());
                          }
                          /**
                           * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
                           * function in the contract matches the call data.
                           */
                          fallback() external payable virtual {
                              _fallback();
                          }
                          /**
                           * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
                           * is empty.
                           */
                          receive() external payable virtual {
                              _fallback();
                          }
                          /**
                           * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
                           * call, or as part of the Solidity `fallback` or `receive` functions.
                           *
                           * If overridden should call `super._beforeFallback()`.
                           */
                          function _beforeFallback() internal virtual {}
                      }
                      // SPDX-License-Identifier: MIT
                      // OpenZeppelin Contracts (last updated v4.8.3) (proxy/transparent/ProxyAdmin.sol)
                      pragma solidity ^0.8.0;
                      import "./TransparentUpgradeableProxy.sol";
                      import "../../access/Ownable.sol";
                      /**
                       * @dev This is an auxiliary contract meant to be assigned as the admin of a {TransparentUpgradeableProxy}. For an
                       * explanation of why you would want to use this see the documentation for {TransparentUpgradeableProxy}.
                       */
                      contract ProxyAdmin is Ownable {
                          /**
                           * @dev Returns the current implementation of `proxy`.
                           *
                           * Requirements:
                           *
                           * - This contract must be the admin of `proxy`.
                           */
                          function getProxyImplementation(ITransparentUpgradeableProxy proxy) public view virtual returns (address) {
                              // We need to manually run the static call since the getter cannot be flagged as view
                              // bytes4(keccak256("implementation()")) == 0x5c60da1b
                              (bool success, bytes memory returndata) = address(proxy).staticcall(hex"5c60da1b");
                              require(success);
                              return abi.decode(returndata, (address));
                          }
                          /**
                           * @dev Returns the current admin of `proxy`.
                           *
                           * Requirements:
                           *
                           * - This contract must be the admin of `proxy`.
                           */
                          function getProxyAdmin(ITransparentUpgradeableProxy proxy) public view virtual returns (address) {
                              // We need to manually run the static call since the getter cannot be flagged as view
                              // bytes4(keccak256("admin()")) == 0xf851a440
                              (bool success, bytes memory returndata) = address(proxy).staticcall(hex"f851a440");
                              require(success);
                              return abi.decode(returndata, (address));
                          }
                          /**
                           * @dev Changes the admin of `proxy` to `newAdmin`.
                           *
                           * Requirements:
                           *
                           * - This contract must be the current admin of `proxy`.
                           */
                          function changeProxyAdmin(ITransparentUpgradeableProxy proxy, address newAdmin) public virtual onlyOwner {
                              proxy.changeAdmin(newAdmin);
                          }
                          /**
                           * @dev Upgrades `proxy` to `implementation`. See {TransparentUpgradeableProxy-upgradeTo}.
                           *
                           * Requirements:
                           *
                           * - This contract must be the admin of `proxy`.
                           */
                          function upgrade(ITransparentUpgradeableProxy proxy, address implementation) public virtual onlyOwner {
                              proxy.upgradeTo(implementation);
                          }
                          /**
                           * @dev Upgrades `proxy` to `implementation` and calls a function on the new implementation. See
                           * {TransparentUpgradeableProxy-upgradeToAndCall}.
                           *
                           * Requirements:
                           *
                           * - This contract must be the admin of `proxy`.
                           */
                          function upgradeAndCall(
                              ITransparentUpgradeableProxy proxy,
                              address implementation,
                              bytes memory data
                          ) public payable virtual onlyOwner {
                              proxy.upgradeToAndCall{value: msg.value}(implementation, data);
                          }
                      }
                      // SPDX-License-Identifier: MIT
                      // OpenZeppelin Contracts (last updated v4.8.3) (proxy/transparent/TransparentUpgradeableProxy.sol)
                      pragma solidity ^0.8.0;
                      import "../ERC1967/ERC1967Proxy.sol";
                      /**
                       * @dev Interface for {TransparentUpgradeableProxy}. In order to implement transparency, {TransparentUpgradeableProxy}
                       * does not implement this interface directly, and some of its functions are implemented by an internal dispatch
                       * mechanism. The compiler is unaware that these functions are implemented by {TransparentUpgradeableProxy} and will not
                       * include them in the ABI so this interface must be used to interact with it.
                       */
                      interface ITransparentUpgradeableProxy is IERC1967 {
                          function admin() external view returns (address);
                          function implementation() external view returns (address);
                          function changeAdmin(address) external;
                          function upgradeTo(address) external;
                          function upgradeToAndCall(address, bytes memory) external payable;
                      }
                      /**
                       * @dev This contract implements a proxy that is upgradeable by an admin.
                       *
                       * To avoid https://medium.com/nomic-labs-blog/malicious-backdoors-in-ethereum-proxies-62629adf3357[proxy selector
                       * clashing], which can potentially be used in an attack, this contract uses the
                       * https://blog.openzeppelin.com/the-transparent-proxy-pattern/[transparent proxy pattern]. This pattern implies two
                       * things that go hand in hand:
                       *
                       * 1. If any account other than the admin calls the proxy, the call will be forwarded to the implementation, even if
                       * that call matches one of the admin functions exposed by the proxy itself.
                       * 2. If the admin calls the proxy, it can access the admin functions, but its calls will never be forwarded to the
                       * implementation. If the admin tries to call a function on the implementation it will fail with an error that says
                       * "admin cannot fallback to proxy target".
                       *
                       * These properties mean that the admin account can only be used for admin actions like upgrading the proxy or changing
                       * the admin, so it's best if it's a dedicated account that is not used for anything else. This will avoid headaches due
                       * to sudden errors when trying to call a function from the proxy implementation.
                       *
                       * Our recommendation is for the dedicated account to be an instance of the {ProxyAdmin} contract. If set up this way,
                       * you should think of the `ProxyAdmin` instance as the real administrative interface of your proxy.
                       *
                       * NOTE: The real interface of this proxy is that defined in `ITransparentUpgradeableProxy`. This contract does not
                       * inherit from that interface, and instead the admin functions are implicitly implemented using a custom dispatch
                       * mechanism in `_fallback`. Consequently, the compiler will not produce an ABI for this contract. This is necessary to
                       * fully implement transparency without decoding reverts caused by selector clashes between the proxy and the
                       * implementation.
                       *
                       * WARNING: It is not recommended to extend this contract to add additional external functions. If you do so, the compiler
                       * will not check that there are no selector conflicts, due to the note above. A selector clash between any new function
                       * and the functions declared in {ITransparentUpgradeableProxy} will be resolved in favor of the new one. This could
                       * render the admin operations inaccessible, which could prevent upgradeability. Transparency may also be compromised.
                       */
                      contract TransparentUpgradeableProxy is ERC1967Proxy {
                          /**
                           * @dev Initializes an upgradeable proxy managed by `_admin`, backed by the implementation at `_logic`, and
                           * optionally initialized with `_data` as explained in {ERC1967Proxy-constructor}.
                           */
                          constructor(
                              address _logic,
                              address admin_,
                              bytes memory _data
                          ) payable ERC1967Proxy(_logic, _data) {
                              _changeAdmin(admin_);
                          }
                          /**
                           * @dev Modifier used internally that will delegate the call to the implementation unless the sender is the admin.
                           *
                           * CAUTION: This modifier is deprecated, as it could cause issues if the modified function has arguments, and the
                           * implementation provides a function with the same selector.
                           */
                          modifier ifAdmin() {
                              if (msg.sender == _getAdmin()) {
                                  _;
                              } else {
                                  _fallback();
                              }
                          }
                          /**
                           * @dev If caller is the admin process the call internally, otherwise transparently fallback to the proxy behavior
                           */
                          function _fallback() internal virtual override {
                              if (msg.sender == _getAdmin()) {
                                  bytes memory ret;
                                  bytes4 selector = msg.sig;
                                  if (selector == ITransparentUpgradeableProxy.upgradeTo.selector) {
                                      ret = _dispatchUpgradeTo();
                                  } else if (selector == ITransparentUpgradeableProxy.upgradeToAndCall.selector) {
                                      ret = _dispatchUpgradeToAndCall();
                                  } else if (selector == ITransparentUpgradeableProxy.changeAdmin.selector) {
                                      ret = _dispatchChangeAdmin();
                                  } else if (selector == ITransparentUpgradeableProxy.admin.selector) {
                                      ret = _dispatchAdmin();
                                  } else if (selector == ITransparentUpgradeableProxy.implementation.selector) {
                                      ret = _dispatchImplementation();
                                  } else {
                                      revert("TransparentUpgradeableProxy: admin cannot fallback to proxy target");
                                  }
                                  assembly {
                                      return(add(ret, 0x20), mload(ret))
                                  }
                              } else {
                                  super._fallback();
                              }
                          }
                          /**
                           * @dev Returns the current admin.
                           *
                           * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
                           * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
                           * `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
                           */
                          function _dispatchAdmin() private returns (bytes memory) {
                              _requireZeroValue();
                              address admin = _getAdmin();
                              return abi.encode(admin);
                          }
                          /**
                           * @dev Returns the current implementation.
                           *
                           * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
                           * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
                           * `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
                           */
                          function _dispatchImplementation() private returns (bytes memory) {
                              _requireZeroValue();
                              address implementation = _implementation();
                              return abi.encode(implementation);
                          }
                          /**
                           * @dev Changes the admin of the proxy.
                           *
                           * Emits an {AdminChanged} event.
                           */
                          function _dispatchChangeAdmin() private returns (bytes memory) {
                              _requireZeroValue();
                              address newAdmin = abi.decode(msg.data[4:], (address));
                              _changeAdmin(newAdmin);
                              return "";
                          }
                          /**
                           * @dev Upgrade the implementation of the proxy.
                           */
                          function _dispatchUpgradeTo() private returns (bytes memory) {
                              _requireZeroValue();
                              address newImplementation = abi.decode(msg.data[4:], (address));
                              _upgradeToAndCall(newImplementation, bytes(""), false);
                              return "";
                          }
                          /**
                           * @dev Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
                           * by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
                           * proxied contract.
                           */
                          function _dispatchUpgradeToAndCall() private returns (bytes memory) {
                              (address newImplementation, bytes memory data) = abi.decode(msg.data[4:], (address, bytes));
                              _upgradeToAndCall(newImplementation, data, true);
                              return "";
                          }
                          /**
                           * @dev Returns the current admin.
                           */
                          function _admin() internal view virtual returns (address) {
                              return _getAdmin();
                          }
                          /**
                           * @dev To keep this contract fully transparent, all `ifAdmin` functions must be payable. This helper is here to
                           * emulate some proxy functions being non-payable while still allowing value to pass through.
                           */
                          function _requireZeroValue() private {
                              require(msg.value == 0);
                          }
                      }
                      // SPDX-License-Identifier: MIT
                      // OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol)
                      pragma solidity ^0.8.1;
                      /**
                       * @dev Collection of functions related to the address type
                       */
                      library Address {
                          /**
                           * @dev Returns true if `account` is a contract.
                           *
                           * [IMPORTANT]
                           * ====
                           * It is unsafe to assume that an address for which this function returns
                           * false is an externally-owned account (EOA) and not a contract.
                           *
                           * Among others, `isContract` will return false for the following
                           * types of addresses:
                           *
                           *  - an externally-owned account
                           *  - a contract in construction
                           *  - an address where a contract will be created
                           *  - an address where a contract lived, but was destroyed
                           * ====
                           *
                           * [IMPORTANT]
                           * ====
                           * You shouldn't rely on `isContract` to protect against flash loan attacks!
                           *
                           * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
                           * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
                           * constructor.
                           * ====
                           */
                          function isContract(address account) internal view returns (bool) {
                              // This method relies on extcodesize/address.code.length, which returns 0
                              // for contracts in construction, since the code is only stored at the end
                              // of the constructor execution.
                              return account.code.length > 0;
                          }
                          /**
                           * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
                           * `recipient`, forwarding all available gas and reverting on errors.
                           *
                           * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
                           * of certain opcodes, possibly making contracts go over the 2300 gas limit
                           * imposed by `transfer`, making them unable to receive funds via
                           * `transfer`. {sendValue} removes this limitation.
                           *
                           * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
                           *
                           * IMPORTANT: because control is transferred to `recipient`, care must be
                           * taken to not create reentrancy vulnerabilities. Consider using
                           * {ReentrancyGuard} or the
                           * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
                           */
                          function sendValue(address payable recipient, uint256 amount) internal {
                              require(address(this).balance >= amount, "Address: insufficient balance");
                              (bool success, ) = recipient.call{value: amount}("");
                              require(success, "Address: unable to send value, recipient may have reverted");
                          }
                          /**
                           * @dev Performs a Solidity function call using a low level `call`. A
                           * plain `call` is an unsafe replacement for a function call: use this
                           * function instead.
                           *
                           * If `target` reverts with a revert reason, it is bubbled up by this
                           * function (like regular Solidity function calls).
                           *
                           * Returns the raw returned data. To convert to the expected return value,
                           * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
                           *
                           * Requirements:
                           *
                           * - `target` must be a contract.
                           * - calling `target` with `data` must not revert.
                           *
                           * _Available since v3.1._
                           */
                          function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                              return 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 v4.7.0) (utils/StorageSlot.sol)
                      pragma solidity ^0.8.0;
                      /**
                       * @dev Library for reading and writing primitive types to specific storage slots.
                       *
                       * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
                       * This library helps with reading and writing to such slots without the need for inline assembly.
                       *
                       * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
                       *
                       * Example usage to set ERC1967 implementation slot:
                       * ```
                       * contract ERC1967 {
                       *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
                       *
                       *     function _getImplementation() internal view returns (address) {
                       *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
                       *     }
                       *
                       *     function _setImplementation(address newImplementation) internal {
                       *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
                       *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
                       *     }
                       * }
                       * ```
                       *
                       * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
                       */
                      library StorageSlot {
                          struct AddressSlot {
                              address value;
                          }
                          struct BooleanSlot {
                              bool value;
                          }
                          struct Bytes32Slot {
                              bytes32 value;
                          }
                          struct Uint256Slot {
                              uint256 value;
                          }
                          /**
                           * @dev Returns an `AddressSlot` with member `value` located at `slot`.
                           */
                          function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
                              /// @solidity memory-safe-assembly
                              assembly {
                                  r.slot := slot
                              }
                          }
                          /**
                           * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
                           */
                          function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
                              /// @solidity memory-safe-assembly
                              assembly {
                                  r.slot := slot
                              }
                          }
                          /**
                           * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
                           */
                          function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
                              /// @solidity memory-safe-assembly
                              assembly {
                                  r.slot := slot
                              }
                          }
                          /**
                           * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
                           */
                          function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
                              /// @solidity memory-safe-assembly
                              assembly {
                                  r.slot := slot
                              }
                          }
                      }
                      

                      File 3 of 4: FiatTokenProxy
                      pragma solidity ^0.4.24;
                      
                      // File: zos-lib/contracts/upgradeability/Proxy.sol
                      
                      /**
                       * @title Proxy
                       * @dev Implements delegation of calls to other contracts, with proper
                       * forwarding of return values and bubbling of failures.
                       * It defines a fallback function that delegates all calls to the address
                       * returned by the abstract _implementation() internal function.
                       */
                      contract Proxy {
                        /**
                         * @dev Fallback function.
                         * Implemented entirely in `_fallback`.
                         */
                        function () payable external {
                          _fallback();
                        }
                      
                        /**
                         * @return The Address of the implementation.
                         */
                        function _implementation() internal view returns (address);
                      
                        /**
                         * @dev Delegates execution to an implementation contract.
                         * This is a low level function that doesn't return to its internal call site.
                         * It will return to the external caller whatever the implementation returns.
                         * @param implementation Address to delegate.
                         */
                        function _delegate(address implementation) internal {
                          assembly {
                            // Copy msg.data. We take full control of memory in this inline assembly
                            // block because it will not return to Solidity code. We overwrite the
                            // Solidity scratch pad at memory position 0.
                            calldatacopy(0, 0, calldatasize)
                      
                            // Call the implementation.
                            // out and outsize are 0 because we don't know the size yet.
                            let result := delegatecall(gas, implementation, 0, calldatasize, 0, 0)
                      
                            // Copy the returned data.
                            returndatacopy(0, 0, returndatasize)
                      
                            switch result
                            // delegatecall returns 0 on error.
                            case 0 { revert(0, returndatasize) }
                            default { return(0, returndatasize) }
                          }
                        }
                      
                        /**
                         * @dev Function that is run as the first thing in the fallback function.
                         * Can be redefined in derived contracts to add functionality.
                         * Redefinitions must call super._willFallback().
                         */
                        function _willFallback() internal {
                        }
                      
                        /**
                         * @dev fallback implementation.
                         * Extracted to enable manual triggering.
                         */
                        function _fallback() internal {
                          _willFallback();
                          _delegate(_implementation());
                        }
                      }
                      
                      // File: openzeppelin-solidity/contracts/AddressUtils.sol
                      
                      /**
                       * Utility library of inline functions on addresses
                       */
                      library AddressUtils {
                      
                        /**
                         * Returns whether the target address is a contract
                         * @dev This function will return false if invoked during the constructor of a contract,
                         * as the code is not actually created until after the constructor finishes.
                         * @param addr address to check
                         * @return whether the target address is a contract
                         */
                        function isContract(address addr) internal view returns (bool) {
                          uint256 size;
                          // XXX Currently there is no better way to check if there is a contract in an address
                          // than to check the size of the code at that address.
                          // See https://ethereum.stackexchange.com/a/14016/36603
                          // for more details about how this works.
                          // TODO Check this again before the Serenity release, because all addresses will be
                          // contracts then.
                          // solium-disable-next-line security/no-inline-assembly
                          assembly { size := extcodesize(addr) }
                          return size > 0;
                        }
                      
                      }
                      
                      // File: zos-lib/contracts/upgradeability/UpgradeabilityProxy.sol
                      
                      /**
                       * @title UpgradeabilityProxy
                       * @dev This contract implements a proxy that allows to change the
                       * implementation address to which it will delegate.
                       * Such a change is called an implementation upgrade.
                       */
                      contract UpgradeabilityProxy is Proxy {
                        /**
                         * @dev Emitted when the implementation is upgraded.
                         * @param implementation Address of the new implementation.
                         */
                        event Upgraded(address implementation);
                      
                        /**
                         * @dev Storage slot with the address of the current implementation.
                         * This is the keccak-256 hash of "org.zeppelinos.proxy.implementation", and is
                         * validated in the constructor.
                         */
                        bytes32 private constant IMPLEMENTATION_SLOT = 0x7050c9e0f4ca769c69bd3a8ef740bc37934f8e2c036e5a723fd8ee048ed3f8c3;
                      
                        /**
                         * @dev Contract constructor.
                         * @param _implementation Address of the initial implementation.
                         */
                        constructor(address _implementation) public {
                          assert(IMPLEMENTATION_SLOT == keccak256("org.zeppelinos.proxy.implementation"));
                      
                          _setImplementation(_implementation);
                        }
                      
                        /**
                         * @dev Returns the current implementation.
                         * @return Address of the current implementation
                         */
                        function _implementation() internal view returns (address impl) {
                          bytes32 slot = IMPLEMENTATION_SLOT;
                          assembly {
                            impl := sload(slot)
                          }
                        }
                      
                        /**
                         * @dev Upgrades the proxy to a new implementation.
                         * @param newImplementation Address of the new implementation.
                         */
                        function _upgradeTo(address newImplementation) internal {
                          _setImplementation(newImplementation);
                          emit Upgraded(newImplementation);
                        }
                      
                        /**
                         * @dev Sets the implementation address of the proxy.
                         * @param newImplementation Address of the new implementation.
                         */
                        function _setImplementation(address newImplementation) private {
                          require(AddressUtils.isContract(newImplementation), "Cannot set a proxy implementation to a non-contract address");
                      
                          bytes32 slot = IMPLEMENTATION_SLOT;
                      
                          assembly {
                            sstore(slot, newImplementation)
                          }
                        }
                      }
                      
                      // File: zos-lib/contracts/upgradeability/AdminUpgradeabilityProxy.sol
                      
                      /**
                       * @title AdminUpgradeabilityProxy
                       * @dev This contract combines an upgradeability proxy with an authorization
                       * mechanism for administrative tasks.
                       * All external functions in this contract must be guarded by the
                       * `ifAdmin` modifier. See ethereum/solidity#3864 for a Solidity
                       * feature proposal that would enable this to be done automatically.
                       */
                      contract AdminUpgradeabilityProxy is UpgradeabilityProxy {
                        /**
                         * @dev Emitted when the administration has been transferred.
                         * @param previousAdmin Address of the previous admin.
                         * @param newAdmin Address of the new admin.
                         */
                        event AdminChanged(address previousAdmin, address newAdmin);
                      
                        /**
                         * @dev Storage slot with the admin of the contract.
                         * This is the keccak-256 hash of "org.zeppelinos.proxy.admin", and is
                         * validated in the constructor.
                         */
                        bytes32 private constant ADMIN_SLOT = 0x10d6a54a4754c8869d6886b5f5d7fbfa5b4522237ea5c60d11bc4e7a1ff9390b;
                      
                        /**
                         * @dev Modifier to check whether the `msg.sender` is the admin.
                         * If it is, it will run the function. Otherwise, it will delegate the call
                         * to the implementation.
                         */
                        modifier ifAdmin() {
                          if (msg.sender == _admin()) {
                            _;
                          } else {
                            _fallback();
                          }
                        }
                      
                        /**
                         * Contract constructor.
                         * It sets the `msg.sender` as the proxy administrator.
                         * @param _implementation address of the initial implementation.
                         */
                        constructor(address _implementation) UpgradeabilityProxy(_implementation) public {
                          assert(ADMIN_SLOT == keccak256("org.zeppelinos.proxy.admin"));
                      
                          _setAdmin(msg.sender);
                        }
                      
                        /**
                         * @return The address of the proxy admin.
                         */
                        function admin() external view ifAdmin returns (address) {
                          return _admin();
                        }
                      
                        /**
                         * @return The address of the implementation.
                         */
                        function implementation() external view ifAdmin returns (address) {
                          return _implementation();
                        }
                      
                        /**
                         * @dev Changes the admin of the proxy.
                         * Only the current admin can call this function.
                         * @param newAdmin Address to transfer proxy administration to.
                         */
                        function changeAdmin(address newAdmin) external ifAdmin {
                          require(newAdmin != address(0), "Cannot change the admin of a proxy to the zero address");
                          emit AdminChanged(_admin(), newAdmin);
                          _setAdmin(newAdmin);
                        }
                      
                        /**
                         * @dev Upgrade the backing implementation of the proxy.
                         * Only the admin can call this function.
                         * @param newImplementation Address of the new implementation.
                         */
                        function upgradeTo(address newImplementation) external ifAdmin {
                          _upgradeTo(newImplementation);
                        }
                      
                        /**
                         * @dev Upgrade the backing implementation of the proxy and call a function
                         * on the new implementation.
                         * This is useful to initialize the proxied contract.
                         * @param newImplementation Address of the new implementation.
                         * @param data Data to send as msg.data in the low level call.
                         * It should include the signature and the parameters of the function to be
                         * called, as described in
                         * https://solidity.readthedocs.io/en/develop/abi-spec.html#function-selector-and-argument-encoding.
                         */
                        function upgradeToAndCall(address newImplementation, bytes data) payable external ifAdmin {
                          _upgradeTo(newImplementation);
                          require(address(this).call.value(msg.value)(data));
                        }
                      
                        /**
                         * @return The admin slot.
                         */
                        function _admin() internal view returns (address adm) {
                          bytes32 slot = ADMIN_SLOT;
                          assembly {
                            adm := sload(slot)
                          }
                        }
                      
                        /**
                         * @dev Sets the address of the proxy admin.
                         * @param newAdmin Address of the new proxy admin.
                         */
                        function _setAdmin(address newAdmin) internal {
                          bytes32 slot = ADMIN_SLOT;
                      
                          assembly {
                            sstore(slot, newAdmin)
                          }
                        }
                      
                        /**
                         * @dev Only fall back when the sender is not the admin.
                         */
                        function _willFallback() internal {
                          require(msg.sender != _admin(), "Cannot call fallback function from the proxy admin");
                          super._willFallback();
                        }
                      }
                      
                      // File: contracts/FiatTokenProxy.sol
                      
                      /**
                      * Copyright CENTRE SECZ 2018
                      *
                      * Permission is hereby granted, free of charge, to any person obtaining a copy 
                      * of this software and associated documentation files (the "Software"), to deal 
                      * in the Software without restriction, including without limitation the rights 
                      * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 
                      * copies of the Software, and to permit persons to whom the Software is furnished to 
                      * do so, subject to the following conditions:
                      *
                      * The above copyright notice and this permission notice shall be included in all 
                      * copies or substantial portions of the Software.
                      *
                      * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
                      * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
                      * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
                      * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
                      * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 
                      * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
                      */
                      
                      pragma solidity ^0.4.24;
                      
                      
                      /**
                       * @title FiatTokenProxy
                       * @dev This contract proxies FiatToken calls and enables FiatToken upgrades
                      */ 
                      contract FiatTokenProxy is AdminUpgradeabilityProxy {
                          constructor(address _implementation) public AdminUpgradeabilityProxy(_implementation) {
                          }
                      }

                      File 4 of 4: FiatTokenV2_2
                      /**
                       * SPDX-License-Identifier: Apache-2.0
                       *
                       * Copyright (c) 2023, Circle Internet Financial, LLC.
                       *
                       * Licensed under the Apache License, Version 2.0 (the "License");
                       * you may not use this file except in compliance with the License.
                       * You may obtain a copy of the License at
                       *
                       * http://www.apache.org/licenses/LICENSE-2.0
                       *
                       * Unless required by applicable law or agreed to in writing, software
                       * distributed under the License is distributed on an "AS IS" BASIS,
                       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                       * See the License for the specific language governing permissions and
                       * limitations under the License.
                       */
                      pragma solidity 0.6.12;
                      import { EIP712Domain } from "./EIP712Domain.sol"; // solhint-disable-line no-unused-import
                      import { Blacklistable } from "../v1/Blacklistable.sol"; // solhint-disable-line no-unused-import
                      import { FiatTokenV1 } from "../v1/FiatTokenV1.sol"; // solhint-disable-line no-unused-import
                      import { FiatTokenV2 } from "./FiatTokenV2.sol"; // solhint-disable-line no-unused-import
                      import { FiatTokenV2_1 } from "./FiatTokenV2_1.sol";
                      import { EIP712 } from "../util/EIP712.sol";
                      // solhint-disable func-name-mixedcase
                      /**
                       * @title FiatToken V2.2
                       * @notice ERC20 Token backed by fiat reserves, version 2.2
                       */
                      contract FiatTokenV2_2 is FiatTokenV2_1 {
                          /**
                           * @notice Initialize v2.2
                           * @param accountsToBlacklist   A list of accounts to migrate from the old blacklist
                           * @param newSymbol             New token symbol
                           * data structure to the new blacklist data structure.
                           */
                          function initializeV2_2(
                              address[] calldata accountsToBlacklist,
                              string calldata newSymbol
                          ) external {
                              // solhint-disable-next-line reason-string
                              require(_initializedVersion == 2);
                              // Update fiat token symbol
                              symbol = newSymbol;
                              // Add previously blacklisted accounts to the new blacklist data structure
                              // and remove them from the old blacklist data structure.
                              for (uint256 i = 0; i < accountsToBlacklist.length; i++) {
                                  require(
                                      _deprecatedBlacklisted[accountsToBlacklist[i]],
                                      "FiatTokenV2_2: Blacklisting previously unblacklisted account!"
                                  );
                                  _blacklist(accountsToBlacklist[i]);
                                  delete _deprecatedBlacklisted[accountsToBlacklist[i]];
                              }
                              _blacklist(address(this));
                              delete _deprecatedBlacklisted[address(this)];
                              _initializedVersion = 3;
                          }
                          /**
                           * @dev Internal function to get the current chain id.
                           * @return The current chain id.
                           */
                          function _chainId() internal virtual view returns (uint256) {
                              uint256 chainId;
                              assembly {
                                  chainId := chainid()
                              }
                              return chainId;
                          }
                          /**
                           * @inheritdoc EIP712Domain
                           */
                          function _domainSeparator() internal override view returns (bytes32) {
                              return EIP712.makeDomainSeparator(name, "2", _chainId());
                          }
                          /**
                           * @notice Update allowance with a signed permit
                           * @dev EOA wallet signatures should be packed in the order of r, s, v.
                           * @param owner       Token owner's address (Authorizer)
                           * @param spender     Spender's address
                           * @param value       Amount of allowance
                           * @param deadline    The time at which the signature expires (unix time), or max uint256 value to signal no expiration
                           * @param signature   Signature bytes signed by an EOA wallet or a contract wallet
                           */
                          function permit(
                              address owner,
                              address spender,
                              uint256 value,
                              uint256 deadline,
                              bytes memory signature
                          ) external whenNotPaused {
                              _permit(owner, spender, value, deadline, signature);
                          }
                          /**
                           * @notice Execute a transfer with a signed authorization
                           * @dev EOA wallet signatures should be packed in the order of r, s, v.
                           * @param from          Payer's address (Authorizer)
                           * @param to            Payee's address
                           * @param value         Amount to be transferred
                           * @param validAfter    The time after which this is valid (unix time)
                           * @param validBefore   The time before which this is valid (unix time)
                           * @param nonce         Unique nonce
                           * @param signature     Signature bytes signed by an EOA wallet or a contract wallet
                           */
                          function transferWithAuthorization(
                              address from,
                              address to,
                              uint256 value,
                              uint256 validAfter,
                              uint256 validBefore,
                              bytes32 nonce,
                              bytes memory signature
                          ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
                              _transferWithAuthorization(
                                  from,
                                  to,
                                  value,
                                  validAfter,
                                  validBefore,
                                  nonce,
                                  signature
                              );
                          }
                          /**
                           * @notice Receive a transfer with a signed authorization from the payer
                           * @dev This has an additional check to ensure that the payee's address
                           * matches the caller of this function to prevent front-running attacks.
                           * EOA wallet signatures should be packed in the order of r, s, v.
                           * @param from          Payer's address (Authorizer)
                           * @param to            Payee's address
                           * @param value         Amount to be transferred
                           * @param validAfter    The time after which this is valid (unix time)
                           * @param validBefore   The time before which this is valid (unix time)
                           * @param nonce         Unique nonce
                           * @param signature     Signature bytes signed by an EOA wallet or a contract wallet
                           */
                          function receiveWithAuthorization(
                              address from,
                              address to,
                              uint256 value,
                              uint256 validAfter,
                              uint256 validBefore,
                              bytes32 nonce,
                              bytes memory signature
                          ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
                              _receiveWithAuthorization(
                                  from,
                                  to,
                                  value,
                                  validAfter,
                                  validBefore,
                                  nonce,
                                  signature
                              );
                          }
                          /**
                           * @notice Attempt to cancel an authorization
                           * @dev Works only if the authorization is not yet used.
                           * EOA wallet signatures should be packed in the order of r, s, v.
                           * @param authorizer    Authorizer's address
                           * @param nonce         Nonce of the authorization
                           * @param signature     Signature bytes signed by an EOA wallet or a contract wallet
                           */
                          function cancelAuthorization(
                              address authorizer,
                              bytes32 nonce,
                              bytes memory signature
                          ) external whenNotPaused {
                              _cancelAuthorization(authorizer, nonce, signature);
                          }
                          /**
                           * @dev Helper method that sets the blacklist state of an account on balanceAndBlacklistStates.
                           * If _shouldBlacklist is true, we apply a (1 << 255) bitmask with an OR operation on the
                           * account's balanceAndBlacklistState. This flips the high bit for the account to 1,
                           * indicating that the account is blacklisted.
                           *
                           * If _shouldBlacklist if false, we reset the account's balanceAndBlacklistStates to their
                           * balances. This clears the high bit for the account, indicating that the account is unblacklisted.
                           * @param _account         The address of the account.
                           * @param _shouldBlacklist True if the account should be blacklisted, false if the account should be unblacklisted.
                           */
                          function _setBlacklistState(address _account, bool _shouldBlacklist)
                              internal
                              override
                          {
                              balanceAndBlacklistStates[_account] = _shouldBlacklist
                                  ? balanceAndBlacklistStates[_account] | (1 << 255)
                                  : _balanceOf(_account);
                          }
                          /**
                           * @dev Helper method that sets the balance of an account on balanceAndBlacklistStates.
                           * Since balances are stored in the last 255 bits of the balanceAndBlacklistStates value,
                           * we need to ensure that the updated balance does not exceed (2^255 - 1).
                           * Since blacklisted accounts' balances cannot be updated, the method will also
                           * revert if the account is blacklisted
                           * @param _account The address of the account.
                           * @param _balance The new fiat token balance of the account (max: (2^255 - 1)).
                           */
                          function _setBalance(address _account, uint256 _balance) internal override {
                              require(
                                  _balance <= ((1 << 255) - 1),
                                  "FiatTokenV2_2: Balance exceeds (2^255 - 1)"
                              );
                              require(
                                  !_isBlacklisted(_account),
                                  "FiatTokenV2_2: Account is blacklisted"
                              );
                              balanceAndBlacklistStates[_account] = _balance;
                          }
                          /**
                           * @inheritdoc Blacklistable
                           */
                          function _isBlacklisted(address _account)
                              internal
                              override
                              view
                              returns (bool)
                          {
                              return balanceAndBlacklistStates[_account] >> 255 == 1;
                          }
                          /**
                           * @dev Helper method to obtain the balance of an account. Since balances
                           * are stored in the last 255 bits of the balanceAndBlacklistStates value,
                           * we apply a ((1 << 255) - 1) bit bitmask with an AND operation on the
                           * balanceAndBlacklistState to obtain the balance.
                           * @param _account  The address of the account.
                           * @return          The fiat token balance of the account.
                           */
                          function _balanceOf(address _account)
                              internal
                              override
                              view
                              returns (uint256)
                          {
                              return balanceAndBlacklistStates[_account] & ((1 << 255) - 1);
                          }
                          /**
                           * @inheritdoc FiatTokenV1
                           */
                          function approve(address spender, uint256 value)
                              external
                              override
                              whenNotPaused
                              returns (bool)
                          {
                              _approve(msg.sender, spender, value);
                              return true;
                          }
                          /**
                           * @inheritdoc FiatTokenV2
                           */
                          function permit(
                              address owner,
                              address spender,
                              uint256 value,
                              uint256 deadline,
                              uint8 v,
                              bytes32 r,
                              bytes32 s
                          ) external override whenNotPaused {
                              _permit(owner, spender, value, deadline, v, r, s);
                          }
                          /**
                           * @inheritdoc FiatTokenV2
                           */
                          function increaseAllowance(address spender, uint256 increment)
                              external
                              override
                              whenNotPaused
                              returns (bool)
                          {
                              _increaseAllowance(msg.sender, spender, increment);
                              return true;
                          }
                          /**
                           * @inheritdoc FiatTokenV2
                           */
                          function decreaseAllowance(address spender, uint256 decrement)
                              external
                              override
                              whenNotPaused
                              returns (bool)
                          {
                              _decreaseAllowance(msg.sender, spender, decrement);
                              return true;
                          }
                      }
                      // SPDX-License-Identifier: MIT
                      pragma solidity >=0.6.2 <0.8.0;
                      /**
                       * @dev Collection of functions related to the address type
                       */
                      library Address {
                          /**
                           * @dev Returns true if `account` is a contract.
                           *
                           * [IMPORTANT]
                           * ====
                           * It is unsafe to assume that an address for which this function returns
                           * false is an externally-owned account (EOA) and not a contract.
                           *
                           * Among others, `isContract` will return false for the following
                           * types of addresses:
                           *
                           *  - an externally-owned account
                           *  - a contract in construction
                           *  - an address where a contract will be created
                           *  - an address where a contract lived, but was destroyed
                           * ====
                           */
                          function isContract(address account) internal view returns (bool) {
                              // This method relies on extcodesize, which returns 0 for contracts in
                              // construction, since the code is only stored at the end of the
                              // constructor execution.
                              uint256 size;
                              // solhint-disable-next-line no-inline-assembly
                              assembly { size := extcodesize(account) }
                              return size > 0;
                          }
                          /**
                           * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
                           * `recipient`, forwarding all available gas and reverting on errors.
                           *
                           * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
                           * of certain opcodes, possibly making contracts go over the 2300 gas limit
                           * imposed by `transfer`, making them unable to receive funds via
                           * `transfer`. {sendValue} removes this limitation.
                           *
                           * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
                           *
                           * IMPORTANT: because control is transferred to `recipient`, care must be
                           * taken to not create reentrancy vulnerabilities. Consider using
                           * {ReentrancyGuard} or the
                           * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
                           */
                          function sendValue(address payable recipient, uint256 amount) internal {
                              require(address(this).balance >= amount, "Address: insufficient balance");
                              // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
                              (bool success, ) = recipient.call{ value: amount }("");
                              require(success, "Address: unable to send value, recipient may have reverted");
                          }
                          /**
                           * @dev Performs a Solidity function call using a low level `call`. A
                           * plain`call` is an unsafe replacement for a function call: use this
                           * function instead.
                           *
                           * If `target` reverts with a revert reason, it is bubbled up by this
                           * function (like regular Solidity function calls).
                           *
                           * Returns the raw returned data. To convert to the expected return value,
                           * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
                           *
                           * Requirements:
                           *
                           * - `target` must be a contract.
                           * - calling `target` with `data` must not revert.
                           *
                           * _Available since v3.1._
                           */
                          function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                            return functionCall(target, data, "Address: low-level call failed");
                          }
                          /**
                           * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
                           * `errorMessage` as a fallback revert reason when `target` reverts.
                           *
                           * _Available since v3.1._
                           */
                          function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                              return functionCallWithValue(target, data, 0, errorMessage);
                          }
                          /**
                           * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                           * but also transferring `value` wei to `target`.
                           *
                           * Requirements:
                           *
                           * - the calling contract must have an ETH balance of at least `value`.
                           * - the called Solidity function must be `payable`.
                           *
                           * _Available since v3.1._
                           */
                          function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
                              return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
                          }
                          /**
                           * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
                           * with `errorMessage` as a fallback revert reason when `target` reverts.
                           *
                           * _Available since v3.1._
                           */
                          function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
                              require(address(this).balance >= value, "Address: insufficient balance for call");
                              require(isContract(target), "Address: call to non-contract");
                              // solhint-disable-next-line avoid-low-level-calls
                              (bool success, bytes memory returndata) = target.call{ value: value }(data);
                              return _verifyCallResult(success, returndata, errorMessage);
                          }
                          /**
                           * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                           * but performing a static call.
                           *
                           * _Available since v3.3._
                           */
                          function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                              return functionStaticCall(target, data, "Address: low-level static call failed");
                          }
                          /**
                           * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                           * but performing a static call.
                           *
                           * _Available since v3.3._
                           */
                          function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
                              require(isContract(target), "Address: static call to non-contract");
                              // solhint-disable-next-line avoid-low-level-calls
                              (bool success, bytes memory returndata) = target.staticcall(data);
                              return _verifyCallResult(success, returndata, errorMessage);
                          }
                          /**
                           * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                           * but performing a delegate call.
                           *
                           * _Available since v3.4._
                           */
                          function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
                              return functionDelegateCall(target, data, "Address: low-level delegate call failed");
                          }
                          /**
                           * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                           * but performing a delegate call.
                           *
                           * _Available since v3.4._
                           */
                          function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                              require(isContract(target), "Address: delegate call to non-contract");
                              // solhint-disable-next-line avoid-low-level-calls
                              (bool success, bytes memory returndata) = target.delegatecall(data);
                              return _verifyCallResult(success, returndata, errorMessage);
                          }
                          function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
                              if (success) {
                                  return returndata;
                              } else {
                                  // Look for revert reason and bubble it up if present
                                  if (returndata.length > 0) {
                                      // The easiest way to bubble the revert reason is using memory via assembly
                                      // solhint-disable-next-line no-inline-assembly
                                      assembly {
                                          let returndata_size := mload(returndata)
                                          revert(add(32, returndata), returndata_size)
                                      }
                                  } else {
                                      revert(errorMessage);
                                  }
                              }
                          }
                      }
                      // SPDX-License-Identifier: MIT
                      pragma solidity >=0.6.0 <0.8.0;
                      import "./IERC20.sol";
                      import "../../math/SafeMath.sol";
                      import "../../utils/Address.sol";
                      /**
                       * @title SafeERC20
                       * @dev Wrappers around ERC20 operations that throw on failure (when the token
                       * contract returns false). Tokens that return no value (and instead revert or
                       * throw on failure) are also supported, non-reverting calls are assumed to be
                       * successful.
                       * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
                       * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
                       */
                      library SafeERC20 {
                          using SafeMath for uint256;
                          using Address for address;
                          function safeTransfer(IERC20 token, address to, uint256 value) internal {
                              _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
                          }
                          function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
                              _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
                          }
                          /**
                           * @dev Deprecated. This function has issues similar to the ones found in
                           * {IERC20-approve}, and its usage is discouraged.
                           *
                           * Whenever possible, use {safeIncreaseAllowance} and
                           * {safeDecreaseAllowance} instead.
                           */
                          function safeApprove(IERC20 token, address spender, uint256 value) internal {
                              // safeApprove should only be called when setting an initial allowance,
                              // or when resetting it to zero. To increase and decrease it, use
                              // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
                              // solhint-disable-next-line max-line-length
                              require((value == 0) || (token.allowance(address(this), spender) == 0),
                                  "SafeERC20: approve from non-zero to non-zero allowance"
                              );
                              _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
                          }
                          function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
                              uint256 newAllowance = token.allowance(address(this), spender).add(value);
                              _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
                          }
                          function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
                              uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
                              _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
                          }
                          /**
                           * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
                           * on the return value: the return value is optional (but if data is returned, it must not be false).
                           * @param token The token targeted by the call.
                           * @param data The call data (encoded using abi.encode or one of its variants).
                           */
                          function _callOptionalReturn(IERC20 token, bytes memory data) private {
                              // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
                              // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
                              // the target address contains contract code and also asserts for success in the low-level call.
                              bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
                              if (returndata.length > 0) { // Return data is optional
                                  // solhint-disable-next-line max-line-length
                                  require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
                              }
                          }
                      }
                      // SPDX-License-Identifier: MIT
                      pragma solidity >=0.6.0 <0.8.0;
                      /**
                       * @dev Interface of the ERC20 standard as defined in the EIP.
                       */
                      interface IERC20 {
                          /**
                           * @dev Returns the amount of tokens in existence.
                           */
                          function totalSupply() external view returns (uint256);
                          /**
                           * @dev Returns the amount of tokens owned by `account`.
                           */
                          function balanceOf(address account) external view returns (uint256);
                          /**
                           * @dev Moves `amount` tokens from the caller's account to `recipient`.
                           *
                           * Returns a boolean value indicating whether the operation succeeded.
                           *
                           * Emits a {Transfer} event.
                           */
                          function transfer(address recipient, uint256 amount) external returns (bool);
                          /**
                           * @dev Returns the remaining number of tokens that `spender` will be
                           * allowed to spend on behalf of `owner` through {transferFrom}. This is
                           * zero by default.
                           *
                           * This value changes when {approve} or {transferFrom} are called.
                           */
                          function allowance(address owner, address spender) external view returns (uint256);
                          /**
                           * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
                           *
                           * Returns a boolean value indicating whether the operation succeeded.
                           *
                           * IMPORTANT: Beware that changing an allowance with this method brings the risk
                           * that someone may use both the old and the new allowance by unfortunate
                           * transaction ordering. One possible solution to mitigate this race
                           * condition is to first reduce the spender's allowance to 0 and set the
                           * desired value afterwards:
                           * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
                           *
                           * Emits an {Approval} event.
                           */
                          function approve(address spender, uint256 amount) external returns (bool);
                          /**
                           * @dev Moves `amount` tokens from `sender` to `recipient` using the
                           * allowance mechanism. `amount` is then deducted from the caller's
                           * allowance.
                           *
                           * Returns a boolean value indicating whether the operation succeeded.
                           *
                           * Emits a {Transfer} event.
                           */
                          function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
                          /**
                           * @dev Emitted when `value` tokens are moved from one account (`from`) to
                           * another (`to`).
                           *
                           * Note that `value` may be zero.
                           */
                          event Transfer(address indexed from, address indexed to, uint256 value);
                          /**
                           * @dev Emitted when the allowance of a `spender` for an `owner` is set by
                           * a call to {approve}. `value` is the new allowance.
                           */
                          event Approval(address indexed owner, address indexed spender, uint256 value);
                      }
                      // SPDX-License-Identifier: MIT
                      pragma solidity >=0.6.0 <0.8.0;
                      /**
                       * @dev Wrappers over Solidity's arithmetic operations with added overflow
                       * checks.
                       *
                       * Arithmetic operations in Solidity wrap on overflow. This can easily result
                       * in bugs, because programmers usually assume that an overflow raises an
                       * error, which is the standard behavior in high level programming languages.
                       * `SafeMath` restores this intuition by reverting the transaction when an
                       * operation overflows.
                       *
                       * Using this library instead of the unchecked operations eliminates an entire
                       * class of bugs, so it's recommended to use it always.
                       */
                      library SafeMath {
                          /**
                           * @dev Returns the addition of two unsigned integers, with an overflow flag.
                           *
                           * _Available since v3.4._
                           */
                          function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                              uint256 c = a + b;
                              if (c < a) return (false, 0);
                              return (true, c);
                          }
                          /**
                           * @dev Returns the substraction of two unsigned integers, with an overflow flag.
                           *
                           * _Available since v3.4._
                           */
                          function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                              if (b > a) return (false, 0);
                              return (true, a - b);
                          }
                          /**
                           * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
                           *
                           * _Available since v3.4._
                           */
                          function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                              // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
                              // benefit is lost if 'b' is also tested.
                              // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
                              if (a == 0) return (true, 0);
                              uint256 c = a * b;
                              if (c / a != b) return (false, 0);
                              return (true, c);
                          }
                          /**
                           * @dev Returns the division of two unsigned integers, with a division by zero flag.
                           *
                           * _Available since v3.4._
                           */
                          function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                              if (b == 0) return (false, 0);
                              return (true, a / b);
                          }
                          /**
                           * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
                           *
                           * _Available since v3.4._
                           */
                          function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                              if (b == 0) return (false, 0);
                              return (true, a % b);
                          }
                          /**
                           * @dev Returns the addition of two unsigned integers, reverting on
                           * overflow.
                           *
                           * Counterpart to Solidity's `+` operator.
                           *
                           * Requirements:
                           *
                           * - Addition cannot overflow.
                           */
                          function add(uint256 a, uint256 b) internal pure returns (uint256) {
                              uint256 c = a + b;
                              require(c >= a, "SafeMath: addition overflow");
                              return c;
                          }
                          /**
                           * @dev Returns the subtraction of two unsigned integers, reverting on
                           * overflow (when the result is negative).
                           *
                           * Counterpart to Solidity's `-` operator.
                           *
                           * Requirements:
                           *
                           * - Subtraction cannot overflow.
                           */
                          function sub(uint256 a, uint256 b) internal pure returns (uint256) {
                              require(b <= a, "SafeMath: subtraction overflow");
                              return a - b;
                          }
                          /**
                           * @dev Returns the multiplication of two unsigned integers, reverting on
                           * overflow.
                           *
                           * Counterpart to Solidity's `*` operator.
                           *
                           * Requirements:
                           *
                           * - Multiplication cannot overflow.
                           */
                          function mul(uint256 a, uint256 b) internal pure returns (uint256) {
                              if (a == 0) return 0;
                              uint256 c = a * b;
                              require(c / a == b, "SafeMath: multiplication overflow");
                              return c;
                          }
                          /**
                           * @dev Returns the integer division of two unsigned integers, reverting on
                           * division by zero. The result is rounded towards zero.
                           *
                           * Counterpart to Solidity's `/` operator. Note: this function uses a
                           * `revert` opcode (which leaves remaining gas untouched) while Solidity
                           * uses an invalid opcode to revert (consuming all remaining gas).
                           *
                           * Requirements:
                           *
                           * - The divisor cannot be zero.
                           */
                          function div(uint256 a, uint256 b) internal pure returns (uint256) {
                              require(b > 0, "SafeMath: division by zero");
                              return a / b;
                          }
                          /**
                           * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
                           * reverting when dividing by zero.
                           *
                           * Counterpart to Solidity's `%` operator. This function uses a `revert`
                           * opcode (which leaves remaining gas untouched) while Solidity uses an
                           * invalid opcode to revert (consuming all remaining gas).
                           *
                           * Requirements:
                           *
                           * - The divisor cannot be zero.
                           */
                          function mod(uint256 a, uint256 b) internal pure returns (uint256) {
                              require(b > 0, "SafeMath: modulo by zero");
                              return a % b;
                          }
                          /**
                           * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
                           * overflow (when the result is negative).
                           *
                           * CAUTION: This function is deprecated because it requires allocating memory for the error
                           * message unnecessarily. For custom revert reasons use {trySub}.
                           *
                           * Counterpart to Solidity's `-` operator.
                           *
                           * Requirements:
                           *
                           * - Subtraction cannot overflow.
                           */
                          function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                              require(b <= a, errorMessage);
                              return a - b;
                          }
                          /**
                           * @dev Returns the integer division of two unsigned integers, reverting with custom message on
                           * division by zero. The result is rounded towards zero.
                           *
                           * CAUTION: This function is deprecated because it requires allocating memory for the error
                           * message unnecessarily. For custom revert reasons use {tryDiv}.
                           *
                           * Counterpart to Solidity's `/` operator. Note: this function uses a
                           * `revert` opcode (which leaves remaining gas untouched) while Solidity
                           * uses an invalid opcode to revert (consuming all remaining gas).
                           *
                           * Requirements:
                           *
                           * - The divisor cannot be zero.
                           */
                          function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                              require(b > 0, errorMessage);
                              return a / b;
                          }
                          /**
                           * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
                           * reverting with custom message when dividing by zero.
                           *
                           * CAUTION: This function is deprecated because it requires allocating memory for the error
                           * message unnecessarily. For custom revert reasons use {tryMod}.
                           *
                           * Counterpart to Solidity's `%` operator. This function uses a `revert`
                           * opcode (which leaves remaining gas untouched) while Solidity uses an
                           * invalid opcode to revert (consuming all remaining gas).
                           *
                           * Requirements:
                           *
                           * - The divisor cannot be zero.
                           */
                          function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                              require(b > 0, errorMessage);
                              return a % b;
                          }
                      }
                      /**
                       * SPDX-License-Identifier: Apache-2.0
                       *
                       * Copyright (c) 2023, Circle Internet Financial, LLC.
                       *
                       * Licensed under the Apache License, Version 2.0 (the "License");
                       * you may not use this file except in compliance with the License.
                       * You may obtain a copy of the License at
                       *
                       * http://www.apache.org/licenses/LICENSE-2.0
                       *
                       * Unless required by applicable law or agreed to in writing, software
                       * distributed under the License is distributed on an "AS IS" BASIS,
                       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                       * See the License for the specific language governing permissions and
                       * limitations under the License.
                       */
                      pragma solidity 0.6.12;
                      import { FiatTokenV2 } from "./FiatTokenV2.sol";
                      // solhint-disable func-name-mixedcase
                      /**
                       * @title FiatToken V2.1
                       * @notice ERC20 Token backed by fiat reserves, version 2.1
                       */
                      contract FiatTokenV2_1 is FiatTokenV2 {
                          /**
                           * @notice Initialize v2.1
                           * @param lostAndFound  The address to which the locked funds are sent
                           */
                          function initializeV2_1(address lostAndFound) external {
                              // solhint-disable-next-line reason-string
                              require(_initializedVersion == 1);
                              uint256 lockedAmount = _balanceOf(address(this));
                              if (lockedAmount > 0) {
                                  _transfer(address(this), lostAndFound, lockedAmount);
                              }
                              _blacklist(address(this));
                              _initializedVersion = 2;
                          }
                          /**
                           * @notice Version string for the EIP712 domain separator
                           * @return Version string
                           */
                          function version() external pure returns (string memory) {
                              return "2";
                          }
                      }
                      /**
                       * SPDX-License-Identifier: Apache-2.0
                       *
                       * Copyright (c) 2023, Circle Internet Financial, LLC.
                       *
                       * Licensed under the Apache License, Version 2.0 (the "License");
                       * you may not use this file except in compliance with the License.
                       * You may obtain a copy of the License at
                       *
                       * http://www.apache.org/licenses/LICENSE-2.0
                       *
                       * Unless required by applicable law or agreed to in writing, software
                       * distributed under the License is distributed on an "AS IS" BASIS,
                       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                       * See the License for the specific language governing permissions and
                       * limitations under the License.
                       */
                      pragma solidity 0.6.12;
                      import { FiatTokenV1_1 } from "../v1.1/FiatTokenV1_1.sol";
                      import { EIP712 } from "../util/EIP712.sol";
                      import { EIP3009 } from "./EIP3009.sol";
                      import { EIP2612 } from "./EIP2612.sol";
                      /**
                       * @title FiatToken V2
                       * @notice ERC20 Token backed by fiat reserves, version 2
                       */
                      contract FiatTokenV2 is FiatTokenV1_1, EIP3009, EIP2612 {
                          uint8 internal _initializedVersion;
                          /**
                           * @notice Initialize v2
                           * @param newName   New token name
                           */
                          function initializeV2(string calldata newName) external {
                              // solhint-disable-next-line reason-string
                              require(initialized && _initializedVersion == 0);
                              name = newName;
                              _DEPRECATED_CACHED_DOMAIN_SEPARATOR = EIP712.makeDomainSeparator(
                                  newName,
                                  "2"
                              );
                              _initializedVersion = 1;
                          }
                          /**
                           * @notice Increase the allowance by a given increment
                           * @param spender   Spender's address
                           * @param increment Amount of increase in allowance
                           * @return True if successful
                           */
                          function increaseAllowance(address spender, uint256 increment)
                              external
                              virtual
                              whenNotPaused
                              notBlacklisted(msg.sender)
                              notBlacklisted(spender)
                              returns (bool)
                          {
                              _increaseAllowance(msg.sender, spender, increment);
                              return true;
                          }
                          /**
                           * @notice Decrease the allowance by a given decrement
                           * @param spender   Spender's address
                           * @param decrement Amount of decrease in allowance
                           * @return True if successful
                           */
                          function decreaseAllowance(address spender, uint256 decrement)
                              external
                              virtual
                              whenNotPaused
                              notBlacklisted(msg.sender)
                              notBlacklisted(spender)
                              returns (bool)
                          {
                              _decreaseAllowance(msg.sender, spender, decrement);
                              return true;
                          }
                          /**
                           * @notice Execute a transfer with a signed authorization
                           * @param from          Payer's address (Authorizer)
                           * @param to            Payee's address
                           * @param value         Amount to be transferred
                           * @param validAfter    The time after which this is valid (unix time)
                           * @param validBefore   The time before which this is valid (unix time)
                           * @param nonce         Unique nonce
                           * @param v             v of the signature
                           * @param r             r of the signature
                           * @param s             s of the signature
                           */
                          function transferWithAuthorization(
                              address from,
                              address to,
                              uint256 value,
                              uint256 validAfter,
                              uint256 validBefore,
                              bytes32 nonce,
                              uint8 v,
                              bytes32 r,
                              bytes32 s
                          ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
                              _transferWithAuthorization(
                                  from,
                                  to,
                                  value,
                                  validAfter,
                                  validBefore,
                                  nonce,
                                  v,
                                  r,
                                  s
                              );
                          }
                          /**
                           * @notice Receive a transfer with a signed authorization from the payer
                           * @dev This has an additional check to ensure that the payee's address
                           * matches the caller of this function to prevent front-running attacks.
                           * @param from          Payer's address (Authorizer)
                           * @param to            Payee's address
                           * @param value         Amount to be transferred
                           * @param validAfter    The time after which this is valid (unix time)
                           * @param validBefore   The time before which this is valid (unix time)
                           * @param nonce         Unique nonce
                           * @param v             v of the signature
                           * @param r             r of the signature
                           * @param s             s of the signature
                           */
                          function receiveWithAuthorization(
                              address from,
                              address to,
                              uint256 value,
                              uint256 validAfter,
                              uint256 validBefore,
                              bytes32 nonce,
                              uint8 v,
                              bytes32 r,
                              bytes32 s
                          ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
                              _receiveWithAuthorization(
                                  from,
                                  to,
                                  value,
                                  validAfter,
                                  validBefore,
                                  nonce,
                                  v,
                                  r,
                                  s
                              );
                          }
                          /**
                           * @notice Attempt to cancel an authorization
                           * @dev Works only if the authorization is not yet used.
                           * @param authorizer    Authorizer's address
                           * @param nonce         Nonce of the authorization
                           * @param v             v of the signature
                           * @param r             r of the signature
                           * @param s             s of the signature
                           */
                          function cancelAuthorization(
                              address authorizer,
                              bytes32 nonce,
                              uint8 v,
                              bytes32 r,
                              bytes32 s
                          ) external whenNotPaused {
                              _cancelAuthorization(authorizer, nonce, v, r, s);
                          }
                          /**
                           * @notice Update allowance with a signed permit
                           * @param owner       Token owner's address (Authorizer)
                           * @param spender     Spender's address
                           * @param value       Amount of allowance
                           * @param deadline    The time at which the signature expires (unix time), or max uint256 value to signal no expiration
                           * @param v           v of the signature
                           * @param r           r of the signature
                           * @param s           s of the signature
                           */
                          function permit(
                              address owner,
                              address spender,
                              uint256 value,
                              uint256 deadline,
                              uint8 v,
                              bytes32 r,
                              bytes32 s
                          )
                              external
                              virtual
                              whenNotPaused
                              notBlacklisted(owner)
                              notBlacklisted(spender)
                          {
                              _permit(owner, spender, value, deadline, v, r, s);
                          }
                          /**
                           * @dev Internal function to increase the allowance by a given increment
                           * @param owner     Token owner's address
                           * @param spender   Spender's address
                           * @param increment Amount of increase
                           */
                          function _increaseAllowance(
                              address owner,
                              address spender,
                              uint256 increment
                          ) internal override {
                              _approve(owner, spender, allowed[owner][spender].add(increment));
                          }
                          /**
                           * @dev Internal function to decrease the allowance by a given decrement
                           * @param owner     Token owner's address
                           * @param spender   Spender's address
                           * @param decrement Amount of decrease
                           */
                          function _decreaseAllowance(
                              address owner,
                              address spender,
                              uint256 decrement
                          ) internal override {
                              _approve(
                                  owner,
                                  spender,
                                  allowed[owner][spender].sub(
                                      decrement,
                                      "ERC20: decreased allowance below zero"
                                  )
                              );
                          }
                      }
                      /**
                       * SPDX-License-Identifier: Apache-2.0
                       *
                       * Copyright (c) 2023, Circle Internet Financial, LLC.
                       *
                       * Licensed under the Apache License, Version 2.0 (the "License");
                       * you may not use this file except in compliance with the License.
                       * You may obtain a copy of the License at
                       *
                       * http://www.apache.org/licenses/LICENSE-2.0
                       *
                       * Unless required by applicable law or agreed to in writing, software
                       * distributed under the License is distributed on an "AS IS" BASIS,
                       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                       * See the License for the specific language governing permissions and
                       * limitations under the License.
                       */
                      pragma solidity 0.6.12;
                      // solhint-disable func-name-mixedcase
                      /**
                       * @title EIP712 Domain
                       */
                      contract EIP712Domain {
                          // was originally DOMAIN_SEPARATOR
                          // but that has been moved to a method so we can override it in V2_2+
                          bytes32 internal _DEPRECATED_CACHED_DOMAIN_SEPARATOR;
                          /**
                           * @notice Get the EIP712 Domain Separator.
                           * @return The bytes32 EIP712 domain separator.
                           */
                          function DOMAIN_SEPARATOR() external view returns (bytes32) {
                              return _domainSeparator();
                          }
                          /**
                           * @dev Internal method to get the EIP712 Domain Separator.
                           * @return The bytes32 EIP712 domain separator.
                           */
                          function _domainSeparator() internal virtual view returns (bytes32) {
                              return _DEPRECATED_CACHED_DOMAIN_SEPARATOR;
                          }
                      }
                      /**
                       * SPDX-License-Identifier: Apache-2.0
                       *
                       * Copyright (c) 2023, Circle Internet Financial, LLC.
                       *
                       * Licensed under the Apache License, Version 2.0 (the "License");
                       * you may not use this file except in compliance with the License.
                       * You may obtain a copy of the License at
                       *
                       * http://www.apache.org/licenses/LICENSE-2.0
                       *
                       * Unless required by applicable law or agreed to in writing, software
                       * distributed under the License is distributed on an "AS IS" BASIS,
                       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                       * See the License for the specific language governing permissions and
                       * limitations under the License.
                       */
                      pragma solidity 0.6.12;
                      import { AbstractFiatTokenV2 } from "./AbstractFiatTokenV2.sol";
                      import { EIP712Domain } from "./EIP712Domain.sol";
                      import { SignatureChecker } from "../util/SignatureChecker.sol";
                      import { MessageHashUtils } from "../util/MessageHashUtils.sol";
                      /**
                       * @title EIP-3009
                       * @notice Provide internal implementation for gas-abstracted transfers
                       * @dev Contracts that inherit from this must wrap these with publicly
                       * accessible functions, optionally adding modifiers where necessary
                       */
                      abstract contract EIP3009 is AbstractFiatTokenV2, EIP712Domain {
                          // keccak256("TransferWithAuthorization(address from,address to,uint256 value,uint256 validAfter,uint256 validBefore,bytes32 nonce)")
                          bytes32
                              public constant TRANSFER_WITH_AUTHORIZATION_TYPEHASH = 0x7c7c6cdb67a18743f49ec6fa9b35f50d52ed05cbed4cc592e13b44501c1a2267;
                          // keccak256("ReceiveWithAuthorization(address from,address to,uint256 value,uint256 validAfter,uint256 validBefore,bytes32 nonce)")
                          bytes32
                              public constant RECEIVE_WITH_AUTHORIZATION_TYPEHASH = 0xd099cc98ef71107a616c4f0f941f04c322d8e254fe26b3c6668db87aae413de8;
                          // keccak256("CancelAuthorization(address authorizer,bytes32 nonce)")
                          bytes32
                              public constant CANCEL_AUTHORIZATION_TYPEHASH = 0x158b0a9edf7a828aad02f63cd515c68ef2f50ba807396f6d12842833a1597429;
                          /**
                           * @dev authorizer address => nonce => bool (true if nonce is used)
                           */
                          mapping(address => mapping(bytes32 => bool)) private _authorizationStates;
                          event AuthorizationUsed(address indexed authorizer, bytes32 indexed nonce);
                          event AuthorizationCanceled(
                              address indexed authorizer,
                              bytes32 indexed nonce
                          );
                          /**
                           * @notice Returns the state of an authorization
                           * @dev Nonces are randomly generated 32-byte data unique to the
                           * authorizer's address
                           * @param authorizer    Authorizer's address
                           * @param nonce         Nonce of the authorization
                           * @return True if the nonce is used
                           */
                          function authorizationState(address authorizer, bytes32 nonce)
                              external
                              view
                              returns (bool)
                          {
                              return _authorizationStates[authorizer][nonce];
                          }
                          /**
                           * @notice Execute a transfer with a signed authorization
                           * @param from          Payer's address (Authorizer)
                           * @param to            Payee's address
                           * @param value         Amount to be transferred
                           * @param validAfter    The time after which this is valid (unix time)
                           * @param validBefore   The time before which this is valid (unix time)
                           * @param nonce         Unique nonce
                           * @param v             v of the signature
                           * @param r             r of the signature
                           * @param s             s of the signature
                           */
                          function _transferWithAuthorization(
                              address from,
                              address to,
                              uint256 value,
                              uint256 validAfter,
                              uint256 validBefore,
                              bytes32 nonce,
                              uint8 v,
                              bytes32 r,
                              bytes32 s
                          ) internal {
                              _transferWithAuthorization(
                                  from,
                                  to,
                                  value,
                                  validAfter,
                                  validBefore,
                                  nonce,
                                  abi.encodePacked(r, s, v)
                              );
                          }
                          /**
                           * @notice Execute a transfer with a signed authorization
                           * @dev EOA wallet signatures should be packed in the order of r, s, v.
                           * @param from          Payer's address (Authorizer)
                           * @param to            Payee's address
                           * @param value         Amount to be transferred
                           * @param validAfter    The time after which this is valid (unix time)
                           * @param validBefore   The time before which this is valid (unix time)
                           * @param nonce         Unique nonce
                           * @param signature     Signature byte array produced by an EOA wallet or a contract wallet
                           */
                          function _transferWithAuthorization(
                              address from,
                              address to,
                              uint256 value,
                              uint256 validAfter,
                              uint256 validBefore,
                              bytes32 nonce,
                              bytes memory signature
                          ) internal {
                              _requireValidAuthorization(from, nonce, validAfter, validBefore);
                              _requireValidSignature(
                                  from,
                                  keccak256(
                                      abi.encode(
                                          TRANSFER_WITH_AUTHORIZATION_TYPEHASH,
                                          from,
                                          to,
                                          value,
                                          validAfter,
                                          validBefore,
                                          nonce
                                      )
                                  ),
                                  signature
                              );
                              _markAuthorizationAsUsed(from, nonce);
                              _transfer(from, to, value);
                          }
                          /**
                           * @notice Receive a transfer with a signed authorization from the payer
                           * @dev This has an additional check to ensure that the payee's address
                           * matches the caller of this function to prevent front-running attacks.
                           * @param from          Payer's address (Authorizer)
                           * @param to            Payee's address
                           * @param value         Amount to be transferred
                           * @param validAfter    The time after which this is valid (unix time)
                           * @param validBefore   The time before which this is valid (unix time)
                           * @param nonce         Unique nonce
                           * @param v             v of the signature
                           * @param r             r of the signature
                           * @param s             s of the signature
                           */
                          function _receiveWithAuthorization(
                              address from,
                              address to,
                              uint256 value,
                              uint256 validAfter,
                              uint256 validBefore,
                              bytes32 nonce,
                              uint8 v,
                              bytes32 r,
                              bytes32 s
                          ) internal {
                              _receiveWithAuthorization(
                                  from,
                                  to,
                                  value,
                                  validAfter,
                                  validBefore,
                                  nonce,
                                  abi.encodePacked(r, s, v)
                              );
                          }
                          /**
                           * @notice Receive a transfer with a signed authorization from the payer
                           * @dev This has an additional check to ensure that the payee's address
                           * matches the caller of this function to prevent front-running attacks.
                           * EOA wallet signatures should be packed in the order of r, s, v.
                           * @param from          Payer's address (Authorizer)
                           * @param to            Payee's address
                           * @param value         Amount to be transferred
                           * @param validAfter    The time after which this is valid (unix time)
                           * @param validBefore   The time before which this is valid (unix time)
                           * @param nonce         Unique nonce
                           * @param signature     Signature byte array produced by an EOA wallet or a contract wallet
                           */
                          function _receiveWithAuthorization(
                              address from,
                              address to,
                              uint256 value,
                              uint256 validAfter,
                              uint256 validBefore,
                              bytes32 nonce,
                              bytes memory signature
                          ) internal {
                              require(to == msg.sender, "FiatTokenV2: caller must be the payee");
                              _requireValidAuthorization(from, nonce, validAfter, validBefore);
                              _requireValidSignature(
                                  from,
                                  keccak256(
                                      abi.encode(
                                          RECEIVE_WITH_AUTHORIZATION_TYPEHASH,
                                          from,
                                          to,
                                          value,
                                          validAfter,
                                          validBefore,
                                          nonce
                                      )
                                  ),
                                  signature
                              );
                              _markAuthorizationAsUsed(from, nonce);
                              _transfer(from, to, value);
                          }
                          /**
                           * @notice Attempt to cancel an authorization
                           * @param authorizer    Authorizer's address
                           * @param nonce         Nonce of the authorization
                           * @param v             v of the signature
                           * @param r             r of the signature
                           * @param s             s of the signature
                           */
                          function _cancelAuthorization(
                              address authorizer,
                              bytes32 nonce,
                              uint8 v,
                              bytes32 r,
                              bytes32 s
                          ) internal {
                              _cancelAuthorization(authorizer, nonce, abi.encodePacked(r, s, v));
                          }
                          /**
                           * @notice Attempt to cancel an authorization
                           * @dev EOA wallet signatures should be packed in the order of r, s, v.
                           * @param authorizer    Authorizer's address
                           * @param nonce         Nonce of the authorization
                           * @param signature     Signature byte array produced by an EOA wallet or a contract wallet
                           */
                          function _cancelAuthorization(
                              address authorizer,
                              bytes32 nonce,
                              bytes memory signature
                          ) internal {
                              _requireUnusedAuthorization(authorizer, nonce);
                              _requireValidSignature(
                                  authorizer,
                                  keccak256(
                                      abi.encode(CANCEL_AUTHORIZATION_TYPEHASH, authorizer, nonce)
                                  ),
                                  signature
                              );
                              _authorizationStates[authorizer][nonce] = true;
                              emit AuthorizationCanceled(authorizer, nonce);
                          }
                          /**
                           * @notice Validates that signature against input data struct
                           * @param signer        Signer's address
                           * @param dataHash      Hash of encoded data struct
                           * @param signature     Signature byte array produced by an EOA wallet or a contract wallet
                           */
                          function _requireValidSignature(
                              address signer,
                              bytes32 dataHash,
                              bytes memory signature
                          ) private view {
                              require(
                                  SignatureChecker.isValidSignatureNow(
                                      signer,
                                      MessageHashUtils.toTypedDataHash(_domainSeparator(), dataHash),
                                      signature
                                  ),
                                  "FiatTokenV2: invalid signature"
                              );
                          }
                          /**
                           * @notice Check that an authorization is unused
                           * @param authorizer    Authorizer's address
                           * @param nonce         Nonce of the authorization
                           */
                          function _requireUnusedAuthorization(address authorizer, bytes32 nonce)
                              private
                              view
                          {
                              require(
                                  !_authorizationStates[authorizer][nonce],
                                  "FiatTokenV2: authorization is used or canceled"
                              );
                          }
                          /**
                           * @notice Check that authorization is valid
                           * @param authorizer    Authorizer's address
                           * @param nonce         Nonce of the authorization
                           * @param validAfter    The time after which this is valid (unix time)
                           * @param validBefore   The time before which this is valid (unix time)
                           */
                          function _requireValidAuthorization(
                              address authorizer,
                              bytes32 nonce,
                              uint256 validAfter,
                              uint256 validBefore
                          ) private view {
                              require(
                                  now > validAfter,
                                  "FiatTokenV2: authorization is not yet valid"
                              );
                              require(now < validBefore, "FiatTokenV2: authorization is expired");
                              _requireUnusedAuthorization(authorizer, nonce);
                          }
                          /**
                           * @notice Mark an authorization as used
                           * @param authorizer    Authorizer's address
                           * @param nonce         Nonce of the authorization
                           */
                          function _markAuthorizationAsUsed(address authorizer, bytes32 nonce)
                              private
                          {
                              _authorizationStates[authorizer][nonce] = true;
                              emit AuthorizationUsed(authorizer, nonce);
                          }
                      }
                      /**
                       * SPDX-License-Identifier: Apache-2.0
                       *
                       * Copyright (c) 2023, Circle Internet Financial, LLC.
                       *
                       * Licensed under the Apache License, Version 2.0 (the "License");
                       * you may not use this file except in compliance with the License.
                       * You may obtain a copy of the License at
                       *
                       * http://www.apache.org/licenses/LICENSE-2.0
                       *
                       * Unless required by applicable law or agreed to in writing, software
                       * distributed under the License is distributed on an "AS IS" BASIS,
                       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                       * See the License for the specific language governing permissions and
                       * limitations under the License.
                       */
                      pragma solidity 0.6.12;
                      import { AbstractFiatTokenV2 } from "./AbstractFiatTokenV2.sol";
                      import { EIP712Domain } from "./EIP712Domain.sol";
                      import { MessageHashUtils } from "../util/MessageHashUtils.sol";
                      import { SignatureChecker } from "../util/SignatureChecker.sol";
                      /**
                       * @title EIP-2612
                       * @notice Provide internal implementation for gas-abstracted approvals
                       */
                      abstract contract EIP2612 is AbstractFiatTokenV2, EIP712Domain {
                          // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)")
                          bytes32
                              public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
                          mapping(address => uint256) private _permitNonces;
                          /**
                           * @notice Nonces for permit
                           * @param owner Token owner's address (Authorizer)
                           * @return Next nonce
                           */
                          function nonces(address owner) external view returns (uint256) {
                              return _permitNonces[owner];
                          }
                          /**
                           * @notice Verify a signed approval permit and execute if valid
                           * @param owner     Token owner's address (Authorizer)
                           * @param spender   Spender's address
                           * @param value     Amount of allowance
                           * @param deadline  The time at which the signature expires (unix time), or max uint256 value to signal no expiration
                           * @param v         v of the signature
                           * @param r         r of the signature
                           * @param s         s of the signature
                           */
                          function _permit(
                              address owner,
                              address spender,
                              uint256 value,
                              uint256 deadline,
                              uint8 v,
                              bytes32 r,
                              bytes32 s
                          ) internal {
                              _permit(owner, spender, value, deadline, abi.encodePacked(r, s, v));
                          }
                          /**
                           * @notice Verify a signed approval permit and execute if valid
                           * @dev EOA wallet signatures should be packed in the order of r, s, v.
                           * @param owner      Token owner's address (Authorizer)
                           * @param spender    Spender's address
                           * @param value      Amount of allowance
                           * @param deadline   The time at which the signature expires (unix time), or max uint256 value to signal no expiration
                           * @param signature  Signature byte array signed by an EOA wallet or a contract wallet
                           */
                          function _permit(
                              address owner,
                              address spender,
                              uint256 value,
                              uint256 deadline,
                              bytes memory signature
                          ) internal {
                              require(
                                  deadline == type(uint256).max || deadline >= now,
                                  "FiatTokenV2: permit is expired"
                              );
                              bytes32 typedDataHash = MessageHashUtils.toTypedDataHash(
                                  _domainSeparator(),
                                  keccak256(
                                      abi.encode(
                                          PERMIT_TYPEHASH,
                                          owner,
                                          spender,
                                          value,
                                          _permitNonces[owner]++,
                                          deadline
                                      )
                                  )
                              );
                              require(
                                  SignatureChecker.isValidSignatureNow(
                                      owner,
                                      typedDataHash,
                                      signature
                                  ),
                                  "EIP2612: invalid signature"
                              );
                              _approve(owner, spender, value);
                          }
                      }
                      /**
                       * SPDX-License-Identifier: Apache-2.0
                       *
                       * Copyright (c) 2023, Circle Internet Financial, LLC.
                       *
                       * Licensed under the Apache License, Version 2.0 (the "License");
                       * you may not use this file except in compliance with the License.
                       * You may obtain a copy of the License at
                       *
                       * http://www.apache.org/licenses/LICENSE-2.0
                       *
                       * Unless required by applicable law or agreed to in writing, software
                       * distributed under the License is distributed on an "AS IS" BASIS,
                       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                       * See the License for the specific language governing permissions and
                       * limitations under the License.
                       */
                      pragma solidity 0.6.12;
                      import { AbstractFiatTokenV1 } from "../v1/AbstractFiatTokenV1.sol";
                      abstract contract AbstractFiatTokenV2 is AbstractFiatTokenV1 {
                          function _increaseAllowance(
                              address owner,
                              address spender,
                              uint256 increment
                          ) internal virtual;
                          function _decreaseAllowance(
                              address owner,
                              address spender,
                              uint256 decrement
                          ) internal virtual;
                      }
                      /**
                       * SPDX-License-Identifier: MIT
                       *
                       * Copyright (c) 2016 Smart Contract Solutions, Inc.
                       * Copyright (c) 2018-2020 CENTRE SECZ
                       *
                       * Permission is hereby granted, free of charge, to any person obtaining a copy
                       * of this software and associated documentation files (the "Software"), to deal
                       * in the Software without restriction, including without limitation the rights
                       * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
                       * copies of the Software, and to permit persons to whom the Software is
                       * furnished to do so, subject to the following conditions:
                       *
                       * The above copyright notice and this permission notice shall be included in
                       * copies or substantial portions of the Software.
                       *
                       * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
                       * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
                       * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
                       * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
                       * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
                       * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
                       * SOFTWARE.
                       */
                      pragma solidity 0.6.12;
                      import { Ownable } from "./Ownable.sol";
                      /**
                       * @notice Base contract which allows children to implement an emergency stop
                       * mechanism
                       * @dev Forked from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/feb665136c0dae9912e08397c1a21c4af3651ef3/contracts/lifecycle/Pausable.sol
                       * Modifications:
                       * 1. Added pauser role, switched pause/unpause to be onlyPauser (6/14/2018)
                       * 2. Removed whenNotPause/whenPaused from pause/unpause (6/14/2018)
                       * 3. Removed whenPaused (6/14/2018)
                       * 4. Switches ownable library to use ZeppelinOS (7/12/18)
                       * 5. Remove constructor (7/13/18)
                       * 6. Reformat, conform to Solidity 0.6 syntax and add error messages (5/13/20)
                       * 7. Make public functions external (5/27/20)
                       */
                      contract Pausable is Ownable {
                          event Pause();
                          event Unpause();
                          event PauserChanged(address indexed newAddress);
                          address public pauser;
                          bool public paused = false;
                          /**
                           * @dev Modifier to make a function callable only when the contract is not paused.
                           */
                          modifier whenNotPaused() {
                              require(!paused, "Pausable: paused");
                              _;
                          }
                          /**
                           * @dev throws if called by any account other than the pauser
                           */
                          modifier onlyPauser() {
                              require(msg.sender == pauser, "Pausable: caller is not the pauser");
                              _;
                          }
                          /**
                           * @dev called by the owner to pause, triggers stopped state
                           */
                          function pause() external onlyPauser {
                              paused = true;
                              emit Pause();
                          }
                          /**
                           * @dev called by the owner to unpause, returns to normal state
                           */
                          function unpause() external onlyPauser {
                              paused = false;
                              emit Unpause();
                          }
                          /**
                           * @notice Updates the pauser address.
                           * @param _newPauser The address of the new pauser.
                           */
                          function updatePauser(address _newPauser) external onlyOwner {
                              require(
                                  _newPauser != address(0),
                                  "Pausable: new pauser is the zero address"
                              );
                              pauser = _newPauser;
                              emit PauserChanged(pauser);
                          }
                      }
                      /**
                       * SPDX-License-Identifier: MIT
                       *
                       * Copyright (c) 2018 zOS Global Limited.
                       * Copyright (c) 2018-2020 CENTRE SECZ
                       *
                       * Permission is hereby granted, free of charge, to any person obtaining a copy
                       * of this software and associated documentation files (the "Software"), to deal
                       * in the Software without restriction, including without limitation the rights
                       * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
                       * copies of the Software, and to permit persons to whom the Software is
                       * furnished to do so, subject to the following conditions:
                       *
                       * The above copyright notice and this permission notice shall be included in
                       * copies or substantial portions of the Software.
                       *
                       * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
                       * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
                       * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
                       * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
                       * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
                       * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
                       * SOFTWARE.
                       */
                      pragma solidity 0.6.12;
                      /**
                       * @notice The Ownable contract has an owner address, and provides basic
                       * authorization control functions
                       * @dev Forked from https://github.com/OpenZeppelin/openzeppelin-labs/blob/3887ab77b8adafba4a26ace002f3a684c1a3388b/upgradeability_ownership/contracts/ownership/Ownable.sol
                       * Modifications:
                       * 1. Consolidate OwnableStorage into this contract (7/13/18)
                       * 2. Reformat, conform to Solidity 0.6 syntax, and add error messages (5/13/20)
                       * 3. Make public functions external (5/27/20)
                       */
                      contract Ownable {
                          // Owner of the contract
                          address private _owner;
                          /**
                           * @dev Event to show ownership has been transferred
                           * @param previousOwner representing the address of the previous owner
                           * @param newOwner representing the address of the new owner
                           */
                          event OwnershipTransferred(address previousOwner, address newOwner);
                          /**
                           * @dev The constructor sets the original owner of the contract to the sender account.
                           */
                          constructor() public {
                              setOwner(msg.sender);
                          }
                          /**
                           * @dev Tells the address of the owner
                           * @return the address of the owner
                           */
                          function owner() external view returns (address) {
                              return _owner;
                          }
                          /**
                           * @dev Sets a new owner address
                           */
                          function setOwner(address newOwner) internal {
                              _owner = newOwner;
                          }
                          /**
                           * @dev Throws if called by any account other than the owner.
                           */
                          modifier onlyOwner() {
                              require(msg.sender == _owner, "Ownable: caller is not the owner");
                              _;
                          }
                          /**
                           * @dev Allows the current owner to transfer control of the contract to a newOwner.
                           * @param newOwner The address to transfer ownership to.
                           */
                          function transferOwnership(address newOwner) external onlyOwner {
                              require(
                                  newOwner != address(0),
                                  "Ownable: new owner is the zero address"
                              );
                              emit OwnershipTransferred(_owner, newOwner);
                              setOwner(newOwner);
                          }
                      }
                      /**
                       * SPDX-License-Identifier: Apache-2.0
                       *
                       * Copyright (c) 2023, Circle Internet Financial, LLC.
                       *
                       * Licensed under the Apache License, Version 2.0 (the "License");
                       * you may not use this file except in compliance with the License.
                       * You may obtain a copy of the License at
                       *
                       * http://www.apache.org/licenses/LICENSE-2.0
                       *
                       * Unless required by applicable law or agreed to in writing, software
                       * distributed under the License is distributed on an "AS IS" BASIS,
                       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                       * See the License for the specific language governing permissions and
                       * limitations under the License.
                       */
                      pragma solidity 0.6.12;
                      import { SafeMath } from "@openzeppelin/contracts/math/SafeMath.sol";
                      import { AbstractFiatTokenV1 } from "./AbstractFiatTokenV1.sol";
                      import { Ownable } from "./Ownable.sol";
                      import { Pausable } from "./Pausable.sol";
                      import { Blacklistable } from "./Blacklistable.sol";
                      /**
                       * @title FiatToken
                       * @dev ERC20 Token backed by fiat reserves
                       */
                      contract FiatTokenV1 is AbstractFiatTokenV1, Ownable, Pausable, Blacklistable {
                          using SafeMath for uint256;
                          string public name;
                          string public symbol;
                          uint8 public decimals;
                          string public currency;
                          address public masterMinter;
                          bool internal initialized;
                          /// @dev A mapping that stores the balance and blacklist states for a given address.
                          /// The first bit defines whether the address is blacklisted (1 if blacklisted, 0 otherwise).
                          /// The last 255 bits define the balance for the address.
                          mapping(address => uint256) internal balanceAndBlacklistStates;
                          mapping(address => mapping(address => uint256)) internal allowed;
                          uint256 internal totalSupply_ = 0;
                          mapping(address => bool) internal minters;
                          mapping(address => uint256) internal minterAllowed;
                          event Mint(address indexed minter, address indexed to, uint256 amount);
                          event Burn(address indexed burner, uint256 amount);
                          event MinterConfigured(address indexed minter, uint256 minterAllowedAmount);
                          event MinterRemoved(address indexed oldMinter);
                          event MasterMinterChanged(address indexed newMasterMinter);
                          /**
                           * @notice Initializes the fiat token contract.
                           * @param tokenName       The name of the fiat token.
                           * @param tokenSymbol     The symbol of the fiat token.
                           * @param tokenCurrency   The fiat currency that the token represents.
                           * @param tokenDecimals   The number of decimals that the token uses.
                           * @param newMasterMinter The masterMinter address for the fiat token.
                           * @param newPauser       The pauser address for the fiat token.
                           * @param newBlacklister  The blacklister address for the fiat token.
                           * @param newOwner        The owner of the fiat token.
                           */
                          function initialize(
                              string memory tokenName,
                              string memory tokenSymbol,
                              string memory tokenCurrency,
                              uint8 tokenDecimals,
                              address newMasterMinter,
                              address newPauser,
                              address newBlacklister,
                              address newOwner
                          ) public {
                              require(!initialized, "FiatToken: contract is already initialized");
                              require(
                                  newMasterMinter != address(0),
                                  "FiatToken: new masterMinter is the zero address"
                              );
                              require(
                                  newPauser != address(0),
                                  "FiatToken: new pauser is the zero address"
                              );
                              require(
                                  newBlacklister != address(0),
                                  "FiatToken: new blacklister is the zero address"
                              );
                              require(
                                  newOwner != address(0),
                                  "FiatToken: new owner is the zero address"
                              );
                              name = tokenName;
                              symbol = tokenSymbol;
                              currency = tokenCurrency;
                              decimals = tokenDecimals;
                              masterMinter = newMasterMinter;
                              pauser = newPauser;
                              blacklister = newBlacklister;
                              setOwner(newOwner);
                              initialized = true;
                          }
                          /**
                           * @dev Throws if called by any account other than a minter.
                           */
                          modifier onlyMinters() {
                              require(minters[msg.sender], "FiatToken: caller is not a minter");
                              _;
                          }
                          /**
                           * @notice Mints fiat tokens to an address.
                           * @param _to The address that will receive the minted tokens.
                           * @param _amount The amount of tokens to mint. Must be less than or equal
                           * to the minterAllowance of the caller.
                           * @return True if the operation was successful.
                           */
                          function mint(address _to, uint256 _amount)
                              external
                              whenNotPaused
                              onlyMinters
                              notBlacklisted(msg.sender)
                              notBlacklisted(_to)
                              returns (bool)
                          {
                              require(_to != address(0), "FiatToken: mint to the zero address");
                              require(_amount > 0, "FiatToken: mint amount not greater than 0");
                              uint256 mintingAllowedAmount = minterAllowed[msg.sender];
                              require(
                                  _amount <= mintingAllowedAmount,
                                  "FiatToken: mint amount exceeds minterAllowance"
                              );
                              totalSupply_ = totalSupply_.add(_amount);
                              _setBalance(_to, _balanceOf(_to).add(_amount));
                              minterAllowed[msg.sender] = mintingAllowedAmount.sub(_amount);
                              emit Mint(msg.sender, _to, _amount);
                              emit Transfer(address(0), _to, _amount);
                              return true;
                          }
                          /**
                           * @dev Throws if called by any account other than the masterMinter
                           */
                          modifier onlyMasterMinter() {
                              require(
                                  msg.sender == masterMinter,
                                  "FiatToken: caller is not the masterMinter"
                              );
                              _;
                          }
                          /**
                           * @notice Gets the minter allowance for an account.
                           * @param minter The address to check.
                           * @return The remaining minter allowance for the account.
                           */
                          function minterAllowance(address minter) external view returns (uint256) {
                              return minterAllowed[minter];
                          }
                          /**
                           * @notice Checks if an account is a minter.
                           * @param account The address to check.
                           * @return True if the account is a minter, false if the account is not a minter.
                           */
                          function isMinter(address account) external view returns (bool) {
                              return minters[account];
                          }
                          /**
                           * @notice Gets the remaining amount of fiat tokens a spender is allowed to transfer on
                           * behalf of the token owner.
                           * @param owner   The token owner's address.
                           * @param spender The spender's address.
                           * @return The remaining allowance.
                           */
                          function allowance(address owner, address spender)
                              external
                              override
                              view
                              returns (uint256)
                          {
                              return allowed[owner][spender];
                          }
                          /**
                           * @notice Gets the totalSupply of the fiat token.
                           * @return The totalSupply of the fiat token.
                           */
                          function totalSupply() external override view returns (uint256) {
                              return totalSupply_;
                          }
                          /**
                           * @notice Gets the fiat token balance of an account.
                           * @param account  The address to check.
                           * @return balance The fiat token balance of the account.
                           */
                          function balanceOf(address account)
                              external
                              override
                              view
                              returns (uint256)
                          {
                              return _balanceOf(account);
                          }
                          /**
                           * @notice Sets a fiat token allowance for a spender to spend on behalf of the caller.
                           * @param spender The spender's address.
                           * @param value   The allowance amount.
                           * @return True if the operation was successful.
                           */
                          function approve(address spender, uint256 value)
                              external
                              virtual
                              override
                              whenNotPaused
                              notBlacklisted(msg.sender)
                              notBlacklisted(spender)
                              returns (bool)
                          {
                              _approve(msg.sender, spender, value);
                              return true;
                          }
                          /**
                           * @dev Internal function to set allowance.
                           * @param owner     Token owner's address.
                           * @param spender   Spender's address.
                           * @param value     Allowance amount.
                           */
                          function _approve(
                              address owner,
                              address spender,
                              uint256 value
                          ) internal override {
                              require(owner != address(0), "ERC20: approve from the zero address");
                              require(spender != address(0), "ERC20: approve to the zero address");
                              allowed[owner][spender] = value;
                              emit Approval(owner, spender, value);
                          }
                          /**
                           * @notice Transfers tokens from an address to another by spending the caller's allowance.
                           * @dev The caller must have some fiat token allowance on the payer's tokens.
                           * @param from  Payer's address.
                           * @param to    Payee's address.
                           * @param value Transfer amount.
                           * @return True if the operation was successful.
                           */
                          function transferFrom(
                              address from,
                              address to,
                              uint256 value
                          )
                              external
                              override
                              whenNotPaused
                              notBlacklisted(msg.sender)
                              notBlacklisted(from)
                              notBlacklisted(to)
                              returns (bool)
                          {
                              require(
                                  value <= allowed[from][msg.sender],
                                  "ERC20: transfer amount exceeds allowance"
                              );
                              _transfer(from, to, value);
                              allowed[from][msg.sender] = allowed[from][msg.sender].sub(value);
                              return true;
                          }
                          /**
                           * @notice Transfers tokens from the caller.
                           * @param to    Payee's address.
                           * @param value Transfer amount.
                           * @return True if the operation was successful.
                           */
                          function transfer(address to, uint256 value)
                              external
                              override
                              whenNotPaused
                              notBlacklisted(msg.sender)
                              notBlacklisted(to)
                              returns (bool)
                          {
                              _transfer(msg.sender, to, value);
                              return true;
                          }
                          /**
                           * @dev Internal function to process transfers.
                           * @param from  Payer's address.
                           * @param to    Payee's address.
                           * @param value Transfer amount.
                           */
                          function _transfer(
                              address from,
                              address to,
                              uint256 value
                          ) internal override {
                              require(from != address(0), "ERC20: transfer from the zero address");
                              require(to != address(0), "ERC20: transfer to the zero address");
                              require(
                                  value <= _balanceOf(from),
                                  "ERC20: transfer amount exceeds balance"
                              );
                              _setBalance(from, _balanceOf(from).sub(value));
                              _setBalance(to, _balanceOf(to).add(value));
                              emit Transfer(from, to, value);
                          }
                          /**
                           * @notice Adds or updates a new minter with a mint allowance.
                           * @param minter The address of the minter.
                           * @param minterAllowedAmount The minting amount allowed for the minter.
                           * @return True if the operation was successful.
                           */
                          function configureMinter(address minter, uint256 minterAllowedAmount)
                              external
                              whenNotPaused
                              onlyMasterMinter
                              returns (bool)
                          {
                              minters[minter] = true;
                              minterAllowed[minter] = minterAllowedAmount;
                              emit MinterConfigured(minter, minterAllowedAmount);
                              return true;
                          }
                          /**
                           * @notice Removes a minter.
                           * @param minter The address of the minter to remove.
                           * @return True if the operation was successful.
                           */
                          function removeMinter(address minter)
                              external
                              onlyMasterMinter
                              returns (bool)
                          {
                              minters[minter] = false;
                              minterAllowed[minter] = 0;
                              emit MinterRemoved(minter);
                              return true;
                          }
                          /**
                           * @notice Allows a minter to burn some of its own tokens.
                           * @dev The caller must be a minter, must not be blacklisted, and the amount to burn
                           * should be less than or equal to the account's balance.
                           * @param _amount the amount of tokens to be burned.
                           */
                          function burn(uint256 _amount)
                              external
                              whenNotPaused
                              onlyMinters
                              notBlacklisted(msg.sender)
                          {
                              uint256 balance = _balanceOf(msg.sender);
                              require(_amount > 0, "FiatToken: burn amount not greater than 0");
                              require(balance >= _amount, "FiatToken: burn amount exceeds balance");
                              totalSupply_ = totalSupply_.sub(_amount);
                              _setBalance(msg.sender, balance.sub(_amount));
                              emit Burn(msg.sender, _amount);
                              emit Transfer(msg.sender, address(0), _amount);
                          }
                          /**
                           * @notice Updates the master minter address.
                           * @param _newMasterMinter The address of the new master minter.
                           */
                          function updateMasterMinter(address _newMasterMinter) external onlyOwner {
                              require(
                                  _newMasterMinter != address(0),
                                  "FiatToken: new masterMinter is the zero address"
                              );
                              masterMinter = _newMasterMinter;
                              emit MasterMinterChanged(masterMinter);
                          }
                          /**
                           * @inheritdoc Blacklistable
                           */
                          function _blacklist(address _account) internal override {
                              _setBlacklistState(_account, true);
                          }
                          /**
                           * @inheritdoc Blacklistable
                           */
                          function _unBlacklist(address _account) internal override {
                              _setBlacklistState(_account, false);
                          }
                          /**
                           * @dev Helper method that sets the blacklist state of an account.
                           * @param _account         The address of the account.
                           * @param _shouldBlacklist True if the account should be blacklisted, false if the account should be unblacklisted.
                           */
                          function _setBlacklistState(address _account, bool _shouldBlacklist)
                              internal
                              virtual
                          {
                              _deprecatedBlacklisted[_account] = _shouldBlacklist;
                          }
                          /**
                           * @dev Helper method that sets the balance of an account.
                           * @param _account The address of the account.
                           * @param _balance The new fiat token balance of the account.
                           */
                          function _setBalance(address _account, uint256 _balance) internal virtual {
                              balanceAndBlacklistStates[_account] = _balance;
                          }
                          /**
                           * @inheritdoc Blacklistable
                           */
                          function _isBlacklisted(address _account)
                              internal
                              virtual
                              override
                              view
                              returns (bool)
                          {
                              return _deprecatedBlacklisted[_account];
                          }
                          /**
                           * @dev Helper method to obtain the balance of an account.
                           * @param _account  The address of the account.
                           * @return          The fiat token balance of the account.
                           */
                          function _balanceOf(address _account)
                              internal
                              virtual
                              view
                              returns (uint256)
                          {
                              return balanceAndBlacklistStates[_account];
                          }
                      }
                      /**
                       * SPDX-License-Identifier: Apache-2.0
                       *
                       * Copyright (c) 2023, Circle Internet Financial, LLC.
                       *
                       * Licensed under the Apache License, Version 2.0 (the "License");
                       * you may not use this file except in compliance with the License.
                       * You may obtain a copy of the License at
                       *
                       * http://www.apache.org/licenses/LICENSE-2.0
                       *
                       * Unless required by applicable law or agreed to in writing, software
                       * distributed under the License is distributed on an "AS IS" BASIS,
                       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                       * See the License for the specific language governing permissions and
                       * limitations under the License.
                       */
                      pragma solidity 0.6.12;
                      import { Ownable } from "./Ownable.sol";
                      /**
                       * @title Blacklistable Token
                       * @dev Allows accounts to be blacklisted by a "blacklister" role
                       */
                      abstract contract Blacklistable is Ownable {
                          address public blacklister;
                          mapping(address => bool) internal _deprecatedBlacklisted;
                          event Blacklisted(address indexed _account);
                          event UnBlacklisted(address indexed _account);
                          event BlacklisterChanged(address indexed newBlacklister);
                          /**
                           * @dev Throws if called by any account other than the blacklister.
                           */
                          modifier onlyBlacklister() {
                              require(
                                  msg.sender == blacklister,
                                  "Blacklistable: caller is not the blacklister"
                              );
                              _;
                          }
                          /**
                           * @dev Throws if argument account is blacklisted.
                           * @param _account The address to check.
                           */
                          modifier notBlacklisted(address _account) {
                              require(
                                  !_isBlacklisted(_account),
                                  "Blacklistable: account is blacklisted"
                              );
                              _;
                          }
                          /**
                           * @notice Checks if account is blacklisted.
                           * @param _account The address to check.
                           * @return True if the account is blacklisted, false if the account is not blacklisted.
                           */
                          function isBlacklisted(address _account) external view returns (bool) {
                              return _isBlacklisted(_account);
                          }
                          /**
                           * @notice Adds account to blacklist.
                           * @param _account The address to blacklist.
                           */
                          function blacklist(address _account) external onlyBlacklister {
                              _blacklist(_account);
                              emit Blacklisted(_account);
                          }
                          /**
                           * @notice Removes account from blacklist.
                           * @param _account The address to remove from the blacklist.
                           */
                          function unBlacklist(address _account) external onlyBlacklister {
                              _unBlacklist(_account);
                              emit UnBlacklisted(_account);
                          }
                          /**
                           * @notice Updates the blacklister address.
                           * @param _newBlacklister The address of the new blacklister.
                           */
                          function updateBlacklister(address _newBlacklister) external onlyOwner {
                              require(
                                  _newBlacklister != address(0),
                                  "Blacklistable: new blacklister is the zero address"
                              );
                              blacklister = _newBlacklister;
                              emit BlacklisterChanged(blacklister);
                          }
                          /**
                           * @dev Checks if account is blacklisted.
                           * @param _account The address to check.
                           * @return true if the account is blacklisted, false otherwise.
                           */
                          function _isBlacklisted(address _account)
                              internal
                              virtual
                              view
                              returns (bool);
                          /**
                           * @dev Helper method that blacklists an account.
                           * @param _account The address to blacklist.
                           */
                          function _blacklist(address _account) internal virtual;
                          /**
                           * @dev Helper method that unblacklists an account.
                           * @param _account The address to unblacklist.
                           */
                          function _unBlacklist(address _account) internal virtual;
                      }
                      /**
                       * SPDX-License-Identifier: Apache-2.0
                       *
                       * Copyright (c) 2023, Circle Internet Financial, LLC.
                       *
                       * Licensed under the Apache License, Version 2.0 (the "License");
                       * you may not use this file except in compliance with the License.
                       * You may obtain a copy of the License at
                       *
                       * http://www.apache.org/licenses/LICENSE-2.0
                       *
                       * Unless required by applicable law or agreed to in writing, software
                       * distributed under the License is distributed on an "AS IS" BASIS,
                       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                       * See the License for the specific language governing permissions and
                       * limitations under the License.
                       */
                      pragma solidity 0.6.12;
                      import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
                      abstract contract AbstractFiatTokenV1 is IERC20 {
                          function _approve(
                              address owner,
                              address spender,
                              uint256 value
                          ) internal virtual;
                          function _transfer(
                              address from,
                              address to,
                              uint256 value
                          ) internal virtual;
                      }
                      /**
                       * SPDX-License-Identifier: Apache-2.0
                       *
                       * Copyright (c) 2023, Circle Internet Financial, LLC.
                       *
                       * Licensed under the Apache License, Version 2.0 (the "License");
                       * you may not use this file except in compliance with the License.
                       * You may obtain a copy of the License at
                       *
                       * http://www.apache.org/licenses/LICENSE-2.0
                       *
                       * Unless required by applicable law or agreed to in writing, software
                       * distributed under the License is distributed on an "AS IS" BASIS,
                       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                       * See the License for the specific language governing permissions and
                       * limitations under the License.
                       */
                      pragma solidity 0.6.12;
                      import { Ownable } from "../v1/Ownable.sol";
                      import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
                      import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
                      contract Rescuable is Ownable {
                          using SafeERC20 for IERC20;
                          address private _rescuer;
                          event RescuerChanged(address indexed newRescuer);
                          /**
                           * @notice Returns current rescuer
                           * @return Rescuer's address
                           */
                          function rescuer() external view returns (address) {
                              return _rescuer;
                          }
                          /**
                           * @notice Revert if called by any account other than the rescuer.
                           */
                          modifier onlyRescuer() {
                              require(msg.sender == _rescuer, "Rescuable: caller is not the rescuer");
                              _;
                          }
                          /**
                           * @notice Rescue ERC20 tokens locked up in this contract.
                           * @param tokenContract ERC20 token contract address
                           * @param to        Recipient address
                           * @param amount    Amount to withdraw
                           */
                          function rescueERC20(
                              IERC20 tokenContract,
                              address to,
                              uint256 amount
                          ) external onlyRescuer {
                              tokenContract.safeTransfer(to, amount);
                          }
                          /**
                           * @notice Updates the rescuer address.
                           * @param newRescuer The address of the new rescuer.
                           */
                          function updateRescuer(address newRescuer) external onlyOwner {
                              require(
                                  newRescuer != address(0),
                                  "Rescuable: new rescuer is the zero address"
                              );
                              _rescuer = newRescuer;
                              emit RescuerChanged(newRescuer);
                          }
                      }
                      /**
                       * SPDX-License-Identifier: Apache-2.0
                       *
                       * Copyright (c) 2023, Circle Internet Financial, LLC.
                       *
                       * Licensed under the Apache License, Version 2.0 (the "License");
                       * you may not use this file except in compliance with the License.
                       * You may obtain a copy of the License at
                       *
                       * http://www.apache.org/licenses/LICENSE-2.0
                       *
                       * Unless required by applicable law or agreed to in writing, software
                       * distributed under the License is distributed on an "AS IS" BASIS,
                       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                       * See the License for the specific language governing permissions and
                       * limitations under the License.
                       */
                      pragma solidity 0.6.12;
                      import { FiatTokenV1 } from "../v1/FiatTokenV1.sol";
                      import { Rescuable } from "./Rescuable.sol";
                      /**
                       * @title FiatTokenV1_1
                       * @dev ERC20 Token backed by fiat reserves
                       */
                      contract FiatTokenV1_1 is FiatTokenV1, Rescuable {
                      }
                      /**
                       * SPDX-License-Identifier: Apache-2.0
                       *
                       * Copyright (c) 2023, Circle Internet Financial, LLC.
                       *
                       * Licensed under the Apache License, Version 2.0 (the "License");
                       * you may not use this file except in compliance with the License.
                       * You may obtain a copy of the License at
                       *
                       * http://www.apache.org/licenses/LICENSE-2.0
                       *
                       * Unless required by applicable law or agreed to in writing, software
                       * distributed under the License is distributed on an "AS IS" BASIS,
                       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                       * See the License for the specific language governing permissions and
                       * limitations under the License.
                       */
                      pragma solidity 0.6.12;
                      import { ECRecover } from "./ECRecover.sol";
                      import { IERC1271 } from "../interface/IERC1271.sol";
                      /**
                       * @dev Signature verification helper that can be used instead of `ECRecover.recover` to seamlessly support both ECDSA
                       * signatures from externally owned accounts (EOAs) as well as ERC1271 signatures from smart contract wallets.
                       *
                       * Adapted from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/21bb89ef5bfc789b9333eb05e3ba2b7b284ac77c/contracts/utils/cryptography/SignatureChecker.sol
                       */
                      library SignatureChecker {
                          /**
                           * @dev Checks if a signature is valid for a given signer and data hash. If the signer is a smart contract, the
                           * signature is validated against that smart contract using ERC1271, otherwise it's validated using `ECRecover.recover`.
                           * @param signer        Address of the claimed signer
                           * @param digest        Keccak-256 hash digest of the signed message
                           * @param signature     Signature byte array associated with hash
                           */
                          function isValidSignatureNow(
                              address signer,
                              bytes32 digest,
                              bytes memory signature
                          ) external view returns (bool) {
                              if (!isContract(signer)) {
                                  return ECRecover.recover(digest, signature) == signer;
                              }
                              return isValidERC1271SignatureNow(signer, digest, signature);
                          }
                          /**
                           * @dev Checks if a signature is valid for a given signer and data hash. The signature is validated
                           * against the signer smart contract using ERC1271.
                           * @param signer        Address of the claimed signer
                           * @param digest        Keccak-256 hash digest of the signed message
                           * @param signature     Signature byte array associated with hash
                           *
                           * NOTE: Unlike ECDSA signatures, contract signatures are revocable, and the outcome of this function can thus
                           * change through time. It could return true at block N and false at block N+1 (or the opposite).
                           */
                          function isValidERC1271SignatureNow(
                              address signer,
                              bytes32 digest,
                              bytes memory signature
                          ) internal view returns (bool) {
                              (bool success, bytes memory result) = signer.staticcall(
                                  abi.encodeWithSelector(
                                      IERC1271.isValidSignature.selector,
                                      digest,
                                      signature
                                  )
                              );
                              return (success &&
                                  result.length >= 32 &&
                                  abi.decode(result, (bytes32)) ==
                                  bytes32(IERC1271.isValidSignature.selector));
                          }
                          /**
                           * @dev Checks if the input address is a smart contract.
                           */
                          function isContract(address addr) internal view returns (bool) {
                              uint256 size;
                              assembly {
                                  size := extcodesize(addr)
                              }
                              return size > 0;
                          }
                      }
                      /**
                       * SPDX-License-Identifier: Apache-2.0
                       *
                       * Copyright (c) 2023, Circle Internet Financial, LLC.
                       *
                       * Licensed under the Apache License, Version 2.0 (the "License");
                       * you may not use this file except in compliance with the License.
                       * You may obtain a copy of the License at
                       *
                       * http://www.apache.org/licenses/LICENSE-2.0
                       *
                       * Unless required by applicable law or agreed to in writing, software
                       * distributed under the License is distributed on an "AS IS" BASIS,
                       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                       * See the License for the specific language governing permissions and
                       * limitations under the License.
                       */
                      pragma solidity 0.6.12;
                      /**
                       * @dev Signature message hash utilities for producing digests to be consumed by {ECDSA} recovery or signing.
                       *
                       * The library provides methods for generating a hash of a message that conforms to the
                       * https://eips.ethereum.org/EIPS/eip-191[EIP 191] and https://eips.ethereum.org/EIPS/eip-712[EIP 712]
                       * specifications.
                       */
                      library MessageHashUtils {
                          /**
                           * @dev Returns the keccak256 digest of an EIP-712 typed data (EIP-191 version `0x01`).
                           * Adapted from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/21bb89ef5bfc789b9333eb05e3ba2b7b284ac77c/contracts/utils/cryptography/MessageHashUtils.sol
                           *
                           * The digest is calculated from a `domainSeparator` and a `structHash`, by prefixing them with
                           * `\\x19\\x01` and hashing the result. It corresponds to the hash signed by the
                           * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`] JSON-RPC method as part of EIP-712.
                           *
                           * @param domainSeparator    Domain separator
                           * @param structHash         Hashed EIP-712 data struct
                           * @return digest            The keccak256 digest of an EIP-712 typed data
                           */
                          function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash)
                              internal
                              pure
                              returns (bytes32 digest)
                          {
                              assembly {
                                  let ptr := mload(0x40)
                                  mstore(ptr, "\\x19\\x01")
                                  mstore(add(ptr, 0x02), domainSeparator)
                                  mstore(add(ptr, 0x22), structHash)
                                  digest := keccak256(ptr, 0x42)
                              }
                          }
                      }
                      /**
                       * SPDX-License-Identifier: Apache-2.0
                       *
                       * Copyright (c) 2023, Circle Internet Financial, LLC.
                       *
                       * Licensed under the Apache License, Version 2.0 (the "License");
                       * you may not use this file except in compliance with the License.
                       * You may obtain a copy of the License at
                       *
                       * http://www.apache.org/licenses/LICENSE-2.0
                       *
                       * Unless required by applicable law or agreed to in writing, software
                       * distributed under the License is distributed on an "AS IS" BASIS,
                       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                       * See the License for the specific language governing permissions and
                       * limitations under the License.
                       */
                      pragma solidity 0.6.12;
                      /**
                       * @title EIP712
                       * @notice A library that provides EIP712 helper functions
                       */
                      library EIP712 {
                          /**
                           * @notice Make EIP712 domain separator
                           * @param name      Contract name
                           * @param version   Contract version
                           * @param chainId   Blockchain ID
                           * @return Domain separator
                           */
                          function makeDomainSeparator(
                              string memory name,
                              string memory version,
                              uint256 chainId
                          ) internal view returns (bytes32) {
                              return
                                  keccak256(
                                      abi.encode(
                                          // keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)")
                                          0x8b73c3c69bb8fe3d512ecc4cf759cc79239f7b179b0ffacaa9a75d522b39400f,
                                          keccak256(bytes(name)),
                                          keccak256(bytes(version)),
                                          chainId,
                                          address(this)
                                      )
                                  );
                          }
                          /**
                           * @notice Make EIP712 domain separator
                           * @param name      Contract name
                           * @param version   Contract version
                           * @return Domain separator
                           */
                          function makeDomainSeparator(string memory name, string memory version)
                              internal
                              view
                              returns (bytes32)
                          {
                              uint256 chainId;
                              assembly {
                                  chainId := chainid()
                              }
                              return makeDomainSeparator(name, version, chainId);
                          }
                      }
                      /**
                       * SPDX-License-Identifier: Apache-2.0
                       *
                       * Copyright (c) 2023, Circle Internet Financial, LLC.
                       *
                       * Licensed under the Apache License, Version 2.0 (the "License");
                       * you may not use this file except in compliance with the License.
                       * You may obtain a copy of the License at
                       *
                       * http://www.apache.org/licenses/LICENSE-2.0
                       *
                       * Unless required by applicable law or agreed to in writing, software
                       * distributed under the License is distributed on an "AS IS" BASIS,
                       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                       * See the License for the specific language governing permissions and
                       * limitations under the License.
                       */
                      pragma solidity 0.6.12;
                      /**
                       * @title ECRecover
                       * @notice A library that provides a safe ECDSA recovery function
                       */
                      library ECRecover {
                          /**
                           * @notice Recover signer's address from a signed message
                           * @dev Adapted from: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/65e4ffde586ec89af3b7e9140bdc9235d1254853/contracts/cryptography/ECDSA.sol
                           * Modifications: Accept v, r, and s as separate arguments
                           * @param digest    Keccak-256 hash digest of the signed message
                           * @param v         v of the signature
                           * @param r         r of the signature
                           * @param s         s of the signature
                           * @return Signer address
                           */
                          function recover(
                              bytes32 digest,
                              uint8 v,
                              bytes32 r,
                              bytes32 s
                          ) internal pure returns (address) {
                              // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
                              // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
                              // the valid range for s in (281): 0 < s < secp256k1n ÷ 2 + 1, and for v in (282): v ∈ {27, 28}. Most
                              // signatures from current libraries generate a unique signature with an s-value in the lower half order.
                              //
                              // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
                              // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
                              // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
                              // these malleable signatures as well.
                              if (
                                  uint256(s) >
                                  0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0
                              ) {
                                  revert("ECRecover: invalid signature 's' value");
                              }
                              if (v != 27 && v != 28) {
                                  revert("ECRecover: invalid signature 'v' value");
                              }
                              // If the signature is valid (and not malleable), return the signer address
                              address signer = ecrecover(digest, v, r, s);
                              require(signer != address(0), "ECRecover: invalid signature");
                              return signer;
                          }
                          /**
                           * @notice Recover signer's address from a signed message
                           * @dev Adapted from: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/0053ee040a7ff1dbc39691c9e67a69f564930a88/contracts/utils/cryptography/ECDSA.sol
                           * @param digest    Keccak-256 hash digest of the signed message
                           * @param signature Signature byte array associated with hash
                           * @return Signer address
                           */
                          function recover(bytes32 digest, bytes memory signature)
                              internal
                              pure
                              returns (address)
                          {
                              require(signature.length == 65, "ECRecover: invalid signature length");
                              bytes32 r;
                              bytes32 s;
                              uint8 v;
                              // ecrecover takes the signature parameters, and the only way to get them
                              // currently is to use assembly.
                              /// @solidity memory-safe-assembly
                              assembly {
                                  r := mload(add(signature, 0x20))
                                  s := mload(add(signature, 0x40))
                                  v := byte(0, mload(add(signature, 0x60)))
                              }
                              return recover(digest, v, r, s);
                          }
                      }
                      /**
                       * SPDX-License-Identifier: Apache-2.0
                       *
                       * Copyright (c) 2023, Circle Internet Financial, LLC.
                       *
                       * Licensed under the Apache License, Version 2.0 (the "License");
                       * you may not use this file except in compliance with the License.
                       * You may obtain a copy of the License at
                       *
                       * http://www.apache.org/licenses/LICENSE-2.0
                       *
                       * Unless required by applicable law or agreed to in writing, software
                       * distributed under the License is distributed on an "AS IS" BASIS,
                       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                       * See the License for the specific language governing permissions and
                       * limitations under the License.
                       */
                      pragma solidity 0.6.12;
                      /**
                       * @dev Interface of the ERC1271 standard signature validation method for
                       * contracts as defined in https://eips.ethereum.org/EIPS/eip-1271[ERC-1271].
                       */
                      interface IERC1271 {
                          /**
                           * @dev Should return whether the signature provided is valid for the provided data
                           * @param hash          Hash of the data to be signed
                           * @param signature     Signature byte array associated with the provided data hash
                           * @return magicValue   bytes4 magic value 0x1626ba7e when function passes
                           */
                          function isValidSignature(bytes32 hash, bytes memory signature)
                              external
                              view
                              returns (bytes4 magicValue);
                      }