ETH Price: $3,165.87 (+6.45%)

Transaction Decoder

Block:
22897907 at Jul-11-2025 07:06:23 PM +UTC
Transaction Fee:
0.000492895404771242 ETH $1.56
Gas Used:
172,282 Gas / 2.860980281 Gwei

Emitted Events:

459 FiatTokenProxy.0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef( 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, 0x000000000000000000000000dd8b0995cc92c7377c7bce2a097ec70f45a192d5, 0x000000000000000000000000f787c16739761a92e11e60e459afaee7ac9941a8, 0000000000000000000000000000000000000000000000000000000037151706 )
460 UUPSProxy.0xd70645d60a6465bb7b8c93d33a3bd06236ce6a6b1ea6111401bb4724dbaaefef( 0xd70645d60a6465bb7b8c93d33a3bd06236ce6a6b1ea6111401bb4724dbaaefef, 000000000000000000000000f787c16739761a92e11e60e459afaee7ac9941a8, 000000000000000000000000a0b86991c6218b36c1d19d4a2e9eb0ce3606eb48, 0000000000000000000000000000000000000000000000000000000037151706 )
461 UUPSProxy.0x99a830bc8dc28151ad5e29ed2c1b05d46849b76a341bf8e0947a46775ba6b4f9( 0x99a830bc8dc28151ad5e29ed2c1b05d46849b76a341bf8e0947a46775ba6b4f9, 0x0000000000000000000000000000000000000000000000000000000000000000, 0x000000000000000000000000a0b86991c6218b36c1d19d4a2e9eb0ce3606eb48, 0000000000000000000000000000000000000000000000000000000037151706, 000000000000000000000000a0b86991c6218b36c1d19d4a2e9eb0ce3606eb48, 0000000000000000000000000000000000000000000000000000000037151706, 000000000000000000000000f787c16739761a92e11e60e459afaee7ac9941a8 )
462 UUPSProxy.0xee823aedb9f54993693aeaca62918fd9eeaf9d0416276706739088c10ceaf2b8( 0xee823aedb9f54993693aeaca62918fd9eeaf9d0416276706739088c10ceaf2b8, 0000000000000000000000000000000000000000000000000000000000000000, 0000000000000000000000000000000000000000000000000000000000000038, 000000000000000000000000000000000000000000000000000000000002268c )

Account State Difference:

  Address   Before After State Difference Code
0x4315f344...1fcA37D57
(XY Finance : YBridge)
(Titan Builder)
16.249389338938413997 Eth16.249389455311803921 Eth0.000000116373389924
0xA0b86991...E3606eB48
0xB35F9aAc...2262db7Da
1.747236006235986896 Eth
Nonce: 21056
1.746743110831215654 Eth
Nonce: 21057
0.000492895404771242

Execution Trace

UUPSProxy.131ea36a( )
  • 0x22c3709560f5f0810e258025218a78f3907cc2c2.131ea36a( )
    • Supervisor.checkSignatures( sigIdHash=C790D98D7A221DD929E88D8A4FAEDA5DEA3B305148F22D7992A3FF99ECA6F6E5, signatures=[S4QZgqLpFJYC1HbYSw0OTCHJfxV8ikE0aBjNybVIrr1/QvLTJw0LLRMnXs5+6oy8LHku96/07FqEtg00tJsH/Rs=, V0FyOjG0XsfGJkbTwhjFIStArloYJyEK4gyDfYbOf2N9ro9CAnYV0mIlgagb1SSnxM8YLeFtHIImfhSrdTJRZhs=, m7fUkv4o/c490/niwre4WEtdf2hlLKblKvyiAuWELAdLRbGPxUZKTUCG9LhqmP7aw/8g1SlBTlGljX6jSyj+/xw=, QT4K+20pwnKLBOrrSWOTIzYXMdKdotL9ZwfcFApfvaw0kSmyjpjDkro/Eihnq+X6mpWmNMvRZTS1QC53/1+wThs=, X6jO09eAkUbr2j6JMny2oNMqQhxpFxcWlEuXkO1MlsVOfpoZJjo/deKaLiTT9NEhu8bV0fYxV4P7edFYQ7bL/Bw=] )
      • Null: 0x000...001.c790d98d( )
      • Null: 0x000...001.c790d98d( )
      • Null: 0x000...001.c790d98d( )
      • Null: 0x000...001.c790d98d( )
      • Null: 0x000...001.c790d98d( )
      • UUPSProxy.a5f2a152( )
        • 0x590c9322a3eb5f96ee9b03227e2091702d5f9b04.a5f2a152( )
          • FiatTokenProxy.a9059cbb( )
            • FiatTokenV2_2.transfer( to=0xF787c16739761A92E11e60E459aFAEe7Ac9941A8, value=924129030 ) => ( True )
              File 1 of 5: UUPSProxy
              // SPDX-License-Identifier: BUSL-1.1
              pragma solidity 0.8.2;
              import "ERC1967Proxy.sol";
              contract UUPSProxy is ERC1967Proxy {
                  constructor(address _logic, bytes memory _data) ERC1967Proxy(_logic, _data) payable {}
              }
              // SPDX-License-Identifier: MIT
              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 initializating the storage of the proxy like a Solidity constructor.
                   */
                  constructor(address _logic, bytes memory _data) payable {
                      assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
                      _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
              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 internall 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 overriden 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 internall 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 overriden should call `super._beforeFallback()`.
                   */
                  function _beforeFallback() internal virtual {}
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.2;
              import "IBeacon.sol";
              import "Address.sol";
              import "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 {
                  // 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 Emitted when the implementation is upgraded.
                   */
                  event Upgraded(address indexed implementation);
                  /**
                   * @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 _upgradeToAndCallSecure(
                      address newImplementation,
                      bytes memory data,
                      bool forceCall
                  ) internal {
                      address oldImplementation = _getImplementation();
                      // Initial upgrade and setup call
                      _setImplementation(newImplementation);
                      if (data.length > 0 || forceCall) {
                          Address.functionDelegateCall(newImplementation, data);
                      }
                      // Perform rollback test if not already in progress
                      StorageSlot.BooleanSlot storage rollbackTesting = StorageSlot.getBooleanSlot(_ROLLBACK_SLOT);
                      if (!rollbackTesting.value) {
                          // Trigger rollback using upgradeTo from the new implementation
                          rollbackTesting.value = true;
                          Address.functionDelegateCall(
                              newImplementation,
                              abi.encodeWithSignature("upgradeTo(address)", oldImplementation)
                          );
                          rollbackTesting.value = false;
                          // Check rollback was effective
                          require(oldImplementation == _getImplementation(), "ERC1967Upgrade: upgrade breaks further upgrades");
                          // Finally reset to the new implementation and log the upgrade
                          _upgradeTo(newImplementation);
                      }
                  }
                  /**
                   * @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 Emitted when the admin account has changed.
                   */
                  event AdminChanged(address previousAdmin, address newAdmin);
                  /**
                   * @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 Emitted when the beacon is upgraded.
                   */
                  event BeaconUpgraded(address indexed beacon);
                  /**
                   * @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
              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
              pragma solidity ^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;
                      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");
                      (bool success, ) = recipient.call{value: amount}("");
                      require(success, "Address: unable to send value, recipient may have reverted");
                  }
                  /**
                   * @dev Performs a Solidity function call using a low level `call`. A
                   * plain `call` is an unsafe replacement for a function call: use this
                   * function instead.
                   *
                   * If `target` reverts with a revert reason, it is bubbled up by this
                   * function (like regular Solidity function calls).
                   *
                   * Returns the raw returned data. To convert to the expected return value,
                   * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
                   *
                   * Requirements:
                   *
                   * - `target` must be a contract.
                   * - calling `target` with `data` must not revert.
                   *
                   * _Available since v3.1._
                   */
                  function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                      return functionCall(target, data, "Address: low-level call failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
                   * `errorMessage` as a fallback revert reason when `target` reverts.
                   *
                   * _Available since v3.1._
                   */
                  function functionCall(
                      address target,
                      bytes memory data,
                      string memory errorMessage
                  ) internal returns (bytes memory) {
                      return functionCallWithValue(target, data, 0, errorMessage);
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                   * but also transferring `value` wei to `target`.
                   *
                   * Requirements:
                   *
                   * - the calling contract must have an ETH balance of at least `value`.
                   * - the called Solidity function must be `payable`.
                   *
                   * _Available since v3.1._
                   */
                  function functionCallWithValue(
                      address target,
                      bytes memory data,
                      uint256 value
                  ) internal returns (bytes memory) {
                      return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
                   * with `errorMessage` as a fallback revert reason when `target` reverts.
                   *
                   * _Available since v3.1._
                   */
                  function functionCallWithValue(
                      address target,
                      bytes memory data,
                      uint256 value,
                      string memory errorMessage
                  ) internal returns (bytes memory) {
                      require(address(this).balance >= value, "Address: insufficient balance for call");
                      require(isContract(target), "Address: call to non-contract");
                      (bool success, bytes memory returndata) = target.call{value: value}(data);
                      return verifyCallResult(success, returndata, errorMessage);
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                   * but performing a static call.
                   *
                   * _Available since v3.3._
                   */
                  function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                      return functionStaticCall(target, data, "Address: low-level static call failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                   * but performing a static call.
                   *
                   * _Available since v3.3._
                   */
                  function functionStaticCall(
                      address target,
                      bytes memory data,
                      string memory errorMessage
                  ) internal view returns (bytes memory) {
                      require(isContract(target), "Address: static call to non-contract");
                      (bool success, bytes memory returndata) = target.staticcall(data);
                      return verifyCallResult(success, returndata, errorMessage);
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                   * but performing a delegate call.
                   *
                   * _Available since v3.4._
                   */
                  function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
                      return functionDelegateCall(target, data, "Address: low-level delegate call failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                   * but performing a delegate call.
                   *
                   * _Available since v3.4._
                   */
                  function functionDelegateCall(
                      address target,
                      bytes memory data,
                      string memory errorMessage
                  ) internal returns (bytes memory) {
                      require(isContract(target), "Address: delegate call to non-contract");
                      (bool success, bytes memory returndata) = target.delegatecall(data);
                      return verifyCallResult(success, returndata, errorMessage);
                  }
                  /**
                   * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
                   * revert reason using the provided one.
                   *
                   * _Available since v4.3._
                   */
                  function verifyCallResult(
                      bool success,
                      bytes memory returndata,
                      string memory errorMessage
                  ) internal pure returns (bytes memory) {
                      if (success) {
                          return returndata;
                      } else {
                          // Look for revert reason and bubble it up if present
                          if (returndata.length > 0) {
                              // The easiest way to bubble the revert reason is using memory via assembly
                              assembly {
                                  let returndata_size := mload(returndata)
                                  revert(add(32, returndata), returndata_size)
                              }
                          } else {
                              revert(errorMessage);
                          }
                      }
                  }
              }
              // SPDX-License-Identifier: MIT
              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) {
                      assembly {
                          r.slot := slot
                      }
                  }
                  /**
                   * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
                   */
                  function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
                      assembly {
                          r.slot := slot
                      }
                  }
                  /**
                   * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
                   */
                  function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
                      assembly {
                          r.slot := slot
                      }
                  }
                  /**
                   * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
                   */
                  function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
                      assembly {
                          r.slot := slot
                      }
                  }
              }
              

              File 2 of 5: FiatTokenProxy
              pragma solidity ^0.4.24;
              
              // File: zos-lib/contracts/upgradeability/Proxy.sol
              
              /**
               * @title Proxy
               * @dev Implements delegation of calls to other contracts, with proper
               * forwarding of return values and bubbling of failures.
               * It defines a fallback function that delegates all calls to the address
               * returned by the abstract _implementation() internal function.
               */
              contract Proxy {
                /**
                 * @dev Fallback function.
                 * Implemented entirely in `_fallback`.
                 */
                function () payable external {
                  _fallback();
                }
              
                /**
                 * @return The Address of the implementation.
                 */
                function _implementation() internal view returns (address);
              
                /**
                 * @dev Delegates execution to an implementation contract.
                 * This is a low level function that doesn't return to its internal call site.
                 * It will return to the external caller whatever the implementation returns.
                 * @param implementation Address to delegate.
                 */
                function _delegate(address implementation) internal {
                  assembly {
                    // Copy msg.data. We take full control of memory in this inline assembly
                    // block because it will not return to Solidity code. We overwrite the
                    // Solidity scratch pad at memory position 0.
                    calldatacopy(0, 0, calldatasize)
              
                    // Call the implementation.
                    // out and outsize are 0 because we don't know the size yet.
                    let result := delegatecall(gas, implementation, 0, calldatasize, 0, 0)
              
                    // Copy the returned data.
                    returndatacopy(0, 0, returndatasize)
              
                    switch result
                    // delegatecall returns 0 on error.
                    case 0 { revert(0, returndatasize) }
                    default { return(0, returndatasize) }
                  }
                }
              
                /**
                 * @dev Function that is run as the first thing in the fallback function.
                 * Can be redefined in derived contracts to add functionality.
                 * Redefinitions must call super._willFallback().
                 */
                function _willFallback() internal {
                }
              
                /**
                 * @dev fallback implementation.
                 * Extracted to enable manual triggering.
                 */
                function _fallback() internal {
                  _willFallback();
                  _delegate(_implementation());
                }
              }
              
              // File: openzeppelin-solidity/contracts/AddressUtils.sol
              
              /**
               * Utility library of inline functions on addresses
               */
              library AddressUtils {
              
                /**
                 * Returns whether the target address is a contract
                 * @dev This function will return false if invoked during the constructor of a contract,
                 * as the code is not actually created until after the constructor finishes.
                 * @param addr address to check
                 * @return whether the target address is a contract
                 */
                function isContract(address addr) internal view returns (bool) {
                  uint256 size;
                  // XXX Currently there is no better way to check if there is a contract in an address
                  // than to check the size of the code at that address.
                  // See https://ethereum.stackexchange.com/a/14016/36603
                  // for more details about how this works.
                  // TODO Check this again before the Serenity release, because all addresses will be
                  // contracts then.
                  // solium-disable-next-line security/no-inline-assembly
                  assembly { size := extcodesize(addr) }
                  return size > 0;
                }
              
              }
              
              // File: zos-lib/contracts/upgradeability/UpgradeabilityProxy.sol
              
              /**
               * @title UpgradeabilityProxy
               * @dev This contract implements a proxy that allows to change the
               * implementation address to which it will delegate.
               * Such a change is called an implementation upgrade.
               */
              contract UpgradeabilityProxy is Proxy {
                /**
                 * @dev Emitted when the implementation is upgraded.
                 * @param implementation Address of the new implementation.
                 */
                event Upgraded(address implementation);
              
                /**
                 * @dev Storage slot with the address of the current implementation.
                 * This is the keccak-256 hash of "org.zeppelinos.proxy.implementation", and is
                 * validated in the constructor.
                 */
                bytes32 private constant IMPLEMENTATION_SLOT = 0x7050c9e0f4ca769c69bd3a8ef740bc37934f8e2c036e5a723fd8ee048ed3f8c3;
              
                /**
                 * @dev Contract constructor.
                 * @param _implementation Address of the initial implementation.
                 */
                constructor(address _implementation) public {
                  assert(IMPLEMENTATION_SLOT == keccak256("org.zeppelinos.proxy.implementation"));
              
                  _setImplementation(_implementation);
                }
              
                /**
                 * @dev Returns the current implementation.
                 * @return Address of the current implementation
                 */
                function _implementation() internal view returns (address impl) {
                  bytes32 slot = IMPLEMENTATION_SLOT;
                  assembly {
                    impl := sload(slot)
                  }
                }
              
                /**
                 * @dev Upgrades the proxy to a new implementation.
                 * @param newImplementation Address of the new implementation.
                 */
                function _upgradeTo(address newImplementation) internal {
                  _setImplementation(newImplementation);
                  emit Upgraded(newImplementation);
                }
              
                /**
                 * @dev Sets the implementation address of the proxy.
                 * @param newImplementation Address of the new implementation.
                 */
                function _setImplementation(address newImplementation) private {
                  require(AddressUtils.isContract(newImplementation), "Cannot set a proxy implementation to a non-contract address");
              
                  bytes32 slot = IMPLEMENTATION_SLOT;
              
                  assembly {
                    sstore(slot, newImplementation)
                  }
                }
              }
              
              // File: zos-lib/contracts/upgradeability/AdminUpgradeabilityProxy.sol
              
              /**
               * @title AdminUpgradeabilityProxy
               * @dev This contract combines an upgradeability proxy with an authorization
               * mechanism for administrative tasks.
               * All external functions in this contract must be guarded by the
               * `ifAdmin` modifier. See ethereum/solidity#3864 for a Solidity
               * feature proposal that would enable this to be done automatically.
               */
              contract AdminUpgradeabilityProxy is UpgradeabilityProxy {
                /**
                 * @dev Emitted when the administration has been transferred.
                 * @param previousAdmin Address of the previous admin.
                 * @param newAdmin Address of the new admin.
                 */
                event AdminChanged(address previousAdmin, address newAdmin);
              
                /**
                 * @dev Storage slot with the admin of the contract.
                 * This is the keccak-256 hash of "org.zeppelinos.proxy.admin", and is
                 * validated in the constructor.
                 */
                bytes32 private constant ADMIN_SLOT = 0x10d6a54a4754c8869d6886b5f5d7fbfa5b4522237ea5c60d11bc4e7a1ff9390b;
              
                /**
                 * @dev Modifier to check whether the `msg.sender` is the admin.
                 * If it is, it will run the function. Otherwise, it will delegate the call
                 * to the implementation.
                 */
                modifier ifAdmin() {
                  if (msg.sender == _admin()) {
                    _;
                  } else {
                    _fallback();
                  }
                }
              
                /**
                 * Contract constructor.
                 * It sets the `msg.sender` as the proxy administrator.
                 * @param _implementation address of the initial implementation.
                 */
                constructor(address _implementation) UpgradeabilityProxy(_implementation) public {
                  assert(ADMIN_SLOT == keccak256("org.zeppelinos.proxy.admin"));
              
                  _setAdmin(msg.sender);
                }
              
                /**
                 * @return The address of the proxy admin.
                 */
                function admin() external view ifAdmin returns (address) {
                  return _admin();
                }
              
                /**
                 * @return The address of the implementation.
                 */
                function implementation() external view ifAdmin returns (address) {
                  return _implementation();
                }
              
                /**
                 * @dev Changes the admin of the proxy.
                 * Only the current admin can call this function.
                 * @param newAdmin Address to transfer proxy administration to.
                 */
                function changeAdmin(address newAdmin) external ifAdmin {
                  require(newAdmin != address(0), "Cannot change the admin of a proxy to the zero address");
                  emit AdminChanged(_admin(), newAdmin);
                  _setAdmin(newAdmin);
                }
              
                /**
                 * @dev Upgrade the backing implementation of the proxy.
                 * Only the admin can call this function.
                 * @param newImplementation Address of the new implementation.
                 */
                function upgradeTo(address newImplementation) external ifAdmin {
                  _upgradeTo(newImplementation);
                }
              
                /**
                 * @dev Upgrade the backing implementation of the proxy and call a function
                 * on the new implementation.
                 * This is useful to initialize the proxied contract.
                 * @param newImplementation Address of the new implementation.
                 * @param data Data to send as msg.data in the low level call.
                 * It should include the signature and the parameters of the function to be
                 * called, as described in
                 * https://solidity.readthedocs.io/en/develop/abi-spec.html#function-selector-and-argument-encoding.
                 */
                function upgradeToAndCall(address newImplementation, bytes data) payable external ifAdmin {
                  _upgradeTo(newImplementation);
                  require(address(this).call.value(msg.value)(data));
                }
              
                /**
                 * @return The admin slot.
                 */
                function _admin() internal view returns (address adm) {
                  bytes32 slot = ADMIN_SLOT;
                  assembly {
                    adm := sload(slot)
                  }
                }
              
                /**
                 * @dev Sets the address of the proxy admin.
                 * @param newAdmin Address of the new proxy admin.
                 */
                function _setAdmin(address newAdmin) internal {
                  bytes32 slot = ADMIN_SLOT;
              
                  assembly {
                    sstore(slot, newAdmin)
                  }
                }
              
                /**
                 * @dev Only fall back when the sender is not the admin.
                 */
                function _willFallback() internal {
                  require(msg.sender != _admin(), "Cannot call fallback function from the proxy admin");
                  super._willFallback();
                }
              }
              
              // File: contracts/FiatTokenProxy.sol
              
              /**
              * Copyright CENTRE SECZ 2018
              *
              * Permission is hereby granted, free of charge, to any person obtaining a copy 
              * of this software and associated documentation files (the "Software"), to deal 
              * in the Software without restriction, including without limitation the rights 
              * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 
              * copies of the Software, and to permit persons to whom the Software is furnished to 
              * do so, subject to the following conditions:
              *
              * The above copyright notice and this permission notice shall be included in all 
              * copies or substantial portions of the Software.
              *
              * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
              * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
              * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
              * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
              * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 
              * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
              */
              
              pragma solidity ^0.4.24;
              
              
              /**
               * @title FiatTokenProxy
               * @dev This contract proxies FiatToken calls and enables FiatToken upgrades
              */ 
              contract FiatTokenProxy is AdminUpgradeabilityProxy {
                  constructor(address _implementation) public AdminUpgradeabilityProxy(_implementation) {
                  }
              }

              File 3 of 5: UUPSProxy
              // SPDX-License-Identifier: BUSL-1.1
              pragma solidity ^0.8.0;
              import "ERC1967Proxy.sol";
              contract UUPSProxy is ERC1967Proxy {
                  constructor(address _logic, bytes memory _data) ERC1967Proxy(_logic, _data) payable {}
              }
              // SPDX-License-Identifier: MIT
              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 initializating the storage of the proxy like a Solidity constructor.
                   */
                  constructor(address _logic, bytes memory _data) payable {
                      assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
                      _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
              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 internall 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 overriden 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 internall 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 overriden should call `super._beforeFallback()`.
                   */
                  function _beforeFallback() internal virtual {}
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.2;
              import "IBeacon.sol";
              import "Address.sol";
              import "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 {
                  // 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 Emitted when the implementation is upgraded.
                   */
                  event Upgraded(address indexed implementation);
                  /**
                   * @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 _upgradeToAndCallSecure(
                      address newImplementation,
                      bytes memory data,
                      bool forceCall
                  ) internal {
                      address oldImplementation = _getImplementation();
                      // Initial upgrade and setup call
                      _setImplementation(newImplementation);
                      if (data.length > 0 || forceCall) {
                          Address.functionDelegateCall(newImplementation, data);
                      }
                      // Perform rollback test if not already in progress
                      StorageSlot.BooleanSlot storage rollbackTesting = StorageSlot.getBooleanSlot(_ROLLBACK_SLOT);
                      if (!rollbackTesting.value) {
                          // Trigger rollback using upgradeTo from the new implementation
                          rollbackTesting.value = true;
                          Address.functionDelegateCall(
                              newImplementation,
                              abi.encodeWithSignature("upgradeTo(address)", oldImplementation)
                          );
                          rollbackTesting.value = false;
                          // Check rollback was effective
                          require(oldImplementation == _getImplementation(), "ERC1967Upgrade: upgrade breaks further upgrades");
                          // Finally reset to the new implementation and log the upgrade
                          _upgradeTo(newImplementation);
                      }
                  }
                  /**
                   * @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 Emitted when the admin account has changed.
                   */
                  event AdminChanged(address previousAdmin, address newAdmin);
                  /**
                   * @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 Emitted when the beacon is upgraded.
                   */
                  event BeaconUpgraded(address indexed beacon);
                  /**
                   * @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
              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
              pragma solidity ^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;
                      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");
                      (bool success, ) = recipient.call{value: amount}("");
                      require(success, "Address: unable to send value, recipient may have reverted");
                  }
                  /**
                   * @dev Performs a Solidity function call using a low level `call`. A
                   * plain `call` is an unsafe replacement for a function call: use this
                   * function instead.
                   *
                   * If `target` reverts with a revert reason, it is bubbled up by this
                   * function (like regular Solidity function calls).
                   *
                   * Returns the raw returned data. To convert to the expected return value,
                   * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
                   *
                   * Requirements:
                   *
                   * - `target` must be a contract.
                   * - calling `target` with `data` must not revert.
                   *
                   * _Available since v3.1._
                   */
                  function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                      return functionCall(target, data, "Address: low-level call failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
                   * `errorMessage` as a fallback revert reason when `target` reverts.
                   *
                   * _Available since v3.1._
                   */
                  function functionCall(
                      address target,
                      bytes memory data,
                      string memory errorMessage
                  ) internal returns (bytes memory) {
                      return functionCallWithValue(target, data, 0, errorMessage);
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                   * but also transferring `value` wei to `target`.
                   *
                   * Requirements:
                   *
                   * - the calling contract must have an ETH balance of at least `value`.
                   * - the called Solidity function must be `payable`.
                   *
                   * _Available since v3.1._
                   */
                  function functionCallWithValue(
                      address target,
                      bytes memory data,
                      uint256 value
                  ) internal returns (bytes memory) {
                      return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
                   * with `errorMessage` as a fallback revert reason when `target` reverts.
                   *
                   * _Available since v3.1._
                   */
                  function functionCallWithValue(
                      address target,
                      bytes memory data,
                      uint256 value,
                      string memory errorMessage
                  ) internal returns (bytes memory) {
                      require(address(this).balance >= value, "Address: insufficient balance for call");
                      require(isContract(target), "Address: call to non-contract");
                      (bool success, bytes memory returndata) = target.call{value: value}(data);
                      return verifyCallResult(success, returndata, errorMessage);
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                   * but performing a static call.
                   *
                   * _Available since v3.3._
                   */
                  function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                      return functionStaticCall(target, data, "Address: low-level static call failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                   * but performing a static call.
                   *
                   * _Available since v3.3._
                   */
                  function functionStaticCall(
                      address target,
                      bytes memory data,
                      string memory errorMessage
                  ) internal view returns (bytes memory) {
                      require(isContract(target), "Address: static call to non-contract");
                      (bool success, bytes memory returndata) = target.staticcall(data);
                      return verifyCallResult(success, returndata, errorMessage);
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                   * but performing a delegate call.
                   *
                   * _Available since v3.4._
                   */
                  function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
                      return functionDelegateCall(target, data, "Address: low-level delegate call failed");
                  }
                  /**
                   * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                   * but performing a delegate call.
                   *
                   * _Available since v3.4._
                   */
                  function functionDelegateCall(
                      address target,
                      bytes memory data,
                      string memory errorMessage
                  ) internal returns (bytes memory) {
                      require(isContract(target), "Address: delegate call to non-contract");
                      (bool success, bytes memory returndata) = target.delegatecall(data);
                      return verifyCallResult(success, returndata, errorMessage);
                  }
                  /**
                   * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
                   * revert reason using the provided one.
                   *
                   * _Available since v4.3._
                   */
                  function verifyCallResult(
                      bool success,
                      bytes memory returndata,
                      string memory errorMessage
                  ) internal pure returns (bytes memory) {
                      if (success) {
                          return returndata;
                      } else {
                          // Look for revert reason and bubble it up if present
                          if (returndata.length > 0) {
                              // The easiest way to bubble the revert reason is using memory via assembly
                              assembly {
                                  let returndata_size := mload(returndata)
                                  revert(add(32, returndata), returndata_size)
                              }
                          } else {
                              revert(errorMessage);
                          }
                      }
                  }
              }
              // SPDX-License-Identifier: MIT
              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) {
                      assembly {
                          r.slot := slot
                      }
                  }
                  /**
                   * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
                   */
                  function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
                      assembly {
                          r.slot := slot
                      }
                  }
                  /**
                   * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
                   */
                  function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
                      assembly {
                          r.slot := slot
                      }
                  }
                  /**
                   * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
                   */
                  function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
                      assembly {
                          r.slot := slot
                      }
                  }
              }
              

              File 4 of 5: Supervisor
              // SPDX-License-Identifier: BUSL-1.1
              pragma solidity ^0.8.0;
              import "ECDSA.sol";
              /// @title Supervisor is the guardian of YPool. It requires multiple validators to valid
              /// the requests from users and workers and sign on them if valid.
              contract Supervisor {
                  using ECDSA for bytes32;
                  /* ========== STATE VARIABLES ========== */
                  bytes32 public constant CLAIM_IDENTIFIER = 'SWAPPER_CLAIM';
                  bytes32 public constant SET_THRESHOLD_IDENTIFIER = 'SET_THRESHOLD';
                  bytes32 public constant SET_VALIDATOR_IDENTIFIER = 'SET_VALIDATOR';
                  bytes32 public constant LOCK_CLOSE_SWAP_AND_REFUND_IDENTIFIER = 'LOCK_CLOSE_SWAP_AND_REFUND';
                  bytes32 public constant BATCH_CLAIM_IDENTIFIER = 'BATCH_CLAIM';
                  bytes32 public constant VALIDATE_SWAP_IDENTIFIER = 'VALIDATE_SWAP_IDENTIFIER';
                  // the chain ID contract located at
                  uint32 public chainId;
                  // check if the address is one of the validators
                  mapping (address => bool) public validators;
                  // number of validators
                  uint256 private validatorsNum;
                  // threshold to pass the signature validation
                  uint256 public threshold;
                  // current nonce for write functions
                  uint256 public nonce;
                  /// @dev Constuctor with chainId / validators / threshold
                  /// @param _chainId The chain ID located with
                  /// @param _validators Initial validator addresses
                  /// @param _threshold Initial threshold to pass the request validation
                  constructor(uint32 _chainId, address [] memory _validators, uint256 _threshold) {
                      chainId = _chainId;
                      for (uint256 i; i < _validators.length; i++) {
                          validators[_validators[i]] = true;
                      }
                      validatorsNum = _validators.length;
                      require(_threshold <= validatorsNum, "ERR_INVALID_THRESHOLD");
                      threshold = _threshold;
                  }
                  /* ========== VIEW FUNCTIONS ========== */
                  /// @notice Check if there are enough signed signatures to the signature hash
                  /// @param sigIdHash The signature hash to be signed
                  /// @param signatures Signed signatures by different validators
                  function checkSignatures(bytes32 sigIdHash, bytes[] memory signatures) public view {
                      require(signatures.length >= threshold, "ERR_NOT_ENOUGH_SIGNATURES");
                      address prevAddress = address(0);
                      for (uint i; i < threshold; i++) {
                          address recovered = sigIdHash.recover(signatures[i]);
                          require(validators[recovered], "ERR_NOT_VALIDATOR");
                          require(recovered > prevAddress, "ERR_WRONG_SIGNER_ORDER");
                          prevAddress = recovered;
                      }
                  }
                  /* ========== WRITE FUNCTIONS ========== */
                  /// @notice Change `threshold` by providing a correct nonce and enough signatures from validators
                  /// @param _threshold New `threshold`
                  /// @param _nonce The nonce to be processed
                  /// @param signatures Signed signatures by validators
                  function setThreshold(uint256 _threshold, uint256 _nonce, bytes[] memory signatures) external {
                      require(signatures.length >= threshold, "ERR_NOT_ENOUGH_SIGNATURES");
                      require(_nonce == nonce, "ERR_INVALID_NONCE");
                      require(_threshold > 0, "ERR_INVALID_THRESHOLD");
                      require(_threshold <= validatorsNum, "ERR_INVALID_THRESHOLD");
                      bytes32 sigId = keccak256(abi.encodePacked(SET_THRESHOLD_IDENTIFIER, address(this), chainId, _threshold, _nonce));
                      bytes32 sigIdHash = sigId.toEthSignedMessageHash();
                      checkSignatures(sigIdHash, signatures);
                      threshold = _threshold;
                      nonce++;
                  }
                  /// @notice Set / remove the validator address to be part of signatures committee
                  /// @param _validator The address to add or remove
                  /// @param flag `true` to add, `false` to remove
                  /// @param _nonce The nonce to be processed
                  /// @param signatures Signed signatures by validators
                  function setValidator(address _validator, bool flag, uint256 _nonce, bytes[] memory signatures) external {
                      require(_validator != address(0), "ERR_INVALID_VALIDATOR");
                      require(signatures.length >= threshold, "ERR_NOT_ENOUGH_SIGNATURES");
                      require(_nonce == nonce, "ERR_INVALID_NONCE");
                      require(flag != validators[_validator], "ERR_OPERATION_TO_VALIDATOR");
                      bytes32 sigId = keccak256(abi.encodePacked(SET_VALIDATOR_IDENTIFIER, address(this), chainId, _validator, flag, _nonce));
                      bytes32 sigIdHash = sigId.toEthSignedMessageHash();
                      checkSignatures(sigIdHash, signatures);
                      if (validators[_validator]) {
                          validatorsNum--;
                          validators[_validator] = false;
                          if (validatorsNum < threshold) threshold--;
                      } else {
                          validatorsNum++;
                          validators[_validator] = true;
                      }
                      nonce++;
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              /**
               * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
               *
               * These functions can be used to verify that a message was signed by the holder
               * of the private keys of a given address.
               */
              library ECDSA {
                  enum RecoverError {
                      NoError,
                      InvalidSignature,
                      InvalidSignatureLength,
                      InvalidSignatureS,
                      InvalidSignatureV
                  }
                  function _throwError(RecoverError error) private pure {
                      if (error == RecoverError.NoError) {
                          return; // no error: do nothing
                      } else if (error == RecoverError.InvalidSignature) {
                          revert("ECDSA: invalid signature");
                      } else if (error == RecoverError.InvalidSignatureLength) {
                          revert("ECDSA: invalid signature length");
                      } else if (error == RecoverError.InvalidSignatureS) {
                          revert("ECDSA: invalid signature 's' value");
                      } else if (error == RecoverError.InvalidSignatureV) {
                          revert("ECDSA: invalid signature 'v' value");
                      }
                  }
                  /**
                   * @dev Returns the address that signed a hashed message (`hash`) with
                   * `signature` or error string. This address can then be used for verification purposes.
                   *
                   * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
                   * this function rejects them by requiring the `s` value to be in the lower
                   * half order, and the `v` value to be either 27 or 28.
                   *
                   * IMPORTANT: `hash` _must_ be the result of a hash operation for the
                   * verification to be secure: it is possible to craft signatures that
                   * recover to arbitrary addresses for non-hashed data. A safe way to ensure
                   * this is by receiving a hash of the original message (which may otherwise
                   * be too long), and then calling {toEthSignedMessageHash} on it.
                   *
                   * Documentation for signature generation:
                   * - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
                   * - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
                   *
                   * _Available since v4.3._
                   */
                  function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) {
                      // Check the signature length
                      // - case 65: r,s,v signature (standard)
                      // - case 64: r,vs signature (cf https://eips.ethereum.org/EIPS/eip-2098) _Available since v4.1._
                      if (signature.length == 65) {
                          bytes32 r;
                          bytes32 s;
                          uint8 v;
                          // ecrecover takes the signature parameters, and the only way to get them
                          // currently is to use assembly.
                          assembly {
                              r := mload(add(signature, 0x20))
                              s := mload(add(signature, 0x40))
                              v := byte(0, mload(add(signature, 0x60)))
                          }
                          return tryRecover(hash, v, r, s);
                      } else if (signature.length == 64) {
                          bytes32 r;
                          bytes32 vs;
                          // ecrecover takes the signature parameters, and the only way to get them
                          // currently is to use assembly.
                          assembly {
                              r := mload(add(signature, 0x20))
                              vs := mload(add(signature, 0x40))
                          }
                          return tryRecover(hash, r, vs);
                      } else {
                          return (address(0), RecoverError.InvalidSignatureLength);
                      }
                  }
                  /**
                   * @dev Returns the address that signed a hashed message (`hash`) with
                   * `signature`. This address can then be used for verification purposes.
                   *
                   * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
                   * this function rejects them by requiring the `s` value to be in the lower
                   * half order, and the `v` value to be either 27 or 28.
                   *
                   * IMPORTANT: `hash` _must_ be the result of a hash operation for the
                   * verification to be secure: it is possible to craft signatures that
                   * recover to arbitrary addresses for non-hashed data. A safe way to ensure
                   * this is by receiving a hash of the original message (which may otherwise
                   * be too long), and then calling {toEthSignedMessageHash} on it.
                   */
                  function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
                      (address recovered, RecoverError error) = tryRecover(hash, signature);
                      _throwError(error);
                      return recovered;
                  }
                  /**
                   * @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
                   *
                   * See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
                   *
                   * _Available since v4.3._
                   */
                  function tryRecover(
                      bytes32 hash,
                      bytes32 r,
                      bytes32 vs
                  ) internal pure returns (address, RecoverError) {
                      bytes32 s;
                      uint8 v;
                      assembly {
                          s := and(vs, 0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff)
                          v := add(shr(255, vs), 27)
                      }
                      return tryRecover(hash, v, r, s);
                  }
                  /**
                   * @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
                   *
                   * _Available since v4.2._
                   */
                  function recover(
                      bytes32 hash,
                      bytes32 r,
                      bytes32 vs
                  ) internal pure returns (address) {
                      (address recovered, RecoverError error) = tryRecover(hash, r, vs);
                      _throwError(error);
                      return recovered;
                  }
                  /**
                   * @dev Overload of {ECDSA-tryRecover} that receives the `v`,
                   * `r` and `s` signature fields separately.
                   *
                   * _Available since v4.3._
                   */
                  function tryRecover(
                      bytes32 hash,
                      uint8 v,
                      bytes32 r,
                      bytes32 s
                  ) internal pure returns (address, RecoverError) {
                      // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
                      // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
                      // the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most
                      // signatures from current libraries generate a unique signature with an s-value in the lower half order.
                      //
                      // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
                      // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
                      // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
                      // these malleable signatures as well.
                      if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
                          return (address(0), RecoverError.InvalidSignatureS);
                      }
                      if (v != 27 && v != 28) {
                          return (address(0), RecoverError.InvalidSignatureV);
                      }
                      // If the signature is valid (and not malleable), return the signer address
                      address signer = ecrecover(hash, v, r, s);
                      if (signer == address(0)) {
                          return (address(0), RecoverError.InvalidSignature);
                      }
                      return (signer, RecoverError.NoError);
                  }
                  /**
                   * @dev Overload of {ECDSA-recover} that receives the `v`,
                   * `r` and `s` signature fields separately.
                   */
                  function recover(
                      bytes32 hash,
                      uint8 v,
                      bytes32 r,
                      bytes32 s
                  ) internal pure returns (address) {
                      (address recovered, RecoverError error) = tryRecover(hash, v, r, s);
                      _throwError(error);
                      return recovered;
                  }
                  /**
                   * @dev Returns an Ethereum Signed Message, created from a `hash`. This
                   * produces hash corresponding to the one signed with the
                   * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
                   * JSON-RPC method as part of EIP-191.
                   *
                   * See {recover}.
                   */
                  function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) {
                      // 32 is the length in bytes of hash,
                      // enforced by the type signature above
                      return keccak256(abi.encodePacked("\\x19Ethereum Signed Message:\
              32", hash));
                  }
                  /**
                   * @dev Returns an Ethereum Signed Typed Data, created from a
                   * `domainSeparator` and a `structHash`. This produces hash corresponding
                   * to the one signed with the
                   * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]
                   * JSON-RPC method as part of EIP-712.
                   *
                   * See {recover}.
                   */
                  function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32) {
                      return keccak256(abi.encodePacked("\\x19\\x01", domainSeparator, structHash));
                  }
              }
              

              File 5 of 5: 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);
              }