ETH Price: $3,287.11 (-3.13%)

Transaction Decoder

Block:
23679344 at Oct-29-2025 12:00:59 AM +UTC
Transaction Fee:
0.000034303487420605 ETH $0.11
Gas Used:
195,557 Gas / 0.175414265 Gwei

Emitted Events:

401 ERC1967Proxy.0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef( 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, 0x000000000000000000000000f6d1b70718596f14870079dcc7da881c753563f5, 0x000000000000000000000000e7c2ab3f0e43f843612d570004984c60ce969a49, 00000000000000000000000000000000000000000000000777e39aa405347dbd )
402 TetherToken.Transfer( from=[Receiver] 0xe7c2ab3f0e43f843612d570004984c60ce969a49, to=[Sender] 0xf6d1b70718596f14870079dcc7da881c753563f5, value=137767042 )
403 0xe7c2ab3f0e43f843612d570004984c60ce969a49.0x8b3e96f2b889fa771c53c981b40daf005f63f637f1869f707052d15a3dd97140( 0x8b3e96f2b889fa771c53c981b40daf005f63f637f1869f707052d15a3dd97140, 0x000000000000000000000000f6d1b70718596f14870079dcc7da881c753563f5, 0000000000000000000000000000000000000000000000000000000000000000, 00000000000000000000000000000000000000000000000777e39aa405347dbd, 0000000000000000000000000000000000000000000000000000000000000001, 0000000000000000000000000000000000000000000000000000000008362882 )

Account State Difference:

  Address   Before After State Difference Code
0xbdC7c085...7D65aDbcD
0xdAC17F95...13D831ec7
(BuilderNet)
64.781469749564986879 Eth64.781487154137986879 Eth0.000017404573
0xe7C2AB3f...0CE969a49
0xf6d1B707...C753563F5
0.846557045377063207 Eth
Nonce: 59
0.846522741889642602 Eth
Nonce: 60
0.000034303487420605

Execution Trace

0xe7c2ab3f0e43f843612d570004984c60ce969a49.3df02124( )
  • Null: 0x000...004.00000000( )
  • Null: 0x000...004.00000000( )
  • ERC1967Proxy.70a08231( )
    • YBSV1_1.balanceOf( account=0xe7C2AB3f0e43f843612D570004984c60CE969a49 ) => ( 98119806246498424684955 )
    • TetherToken.balanceOf( who=0xe7C2AB3f0e43f843612D570004984c60CE969a49 ) => ( 106600649559 )
    • Null: 0x000...004.00000000( )
    • Null: 0x000...004.00000000( )
    • Null: 0x000...004.00000000( )
    • Null: 0x000...004.00000000( )
    • Null: 0x000...004.00000000( )
    • Null: 0x000...004.00000000( )
    • ERC1967Proxy.70a08231( )
      • YBSV1_1.balanceOf( account=0xe7C2AB3f0e43f843612D570004984c60CE969a49 ) => ( 98119806246498424684955 )
      • ERC1967Proxy.23b872dd( )
        • YBSV1_1.transferFrom( from=0xf6d1B70718596F14870079dCc7da881C753563F5, to=0xe7C2AB3f0e43f843612D570004984c60CE969a49, amount=137766127055446244797 ) => ( True )
        • ERC1967Proxy.70a08231( )
          • YBSV1_1.balanceOf( account=0xe7C2AB3f0e43f843612D570004984c60CE969a49 ) => ( 98257572373553870929752 )
          • Null: 0x000...004.00000000( )
          • Null: 0x000...004.00000000( )
          • Null: 0x000...004.00000000( )
          • Null: 0x000...004.00000000( )
          • Null: 0x000...004.00000000( )
          • Null: 0x000...004.00000000( )
          • Null: 0x000...004.00000000( )
          • Null: 0x000...004.00000000( )
          • Null: 0x000...004.00000000( )
          • Null: 0x000...004.00000000( )
          • Null: 0x000...004.00000000( )
          • Null: 0x000...004.00000000( )
          • Null: 0x000...004.00000000( )
          • TetherToken.balanceOf( who=0xe7C2AB3f0e43f843612D570004984c60CE969a49 ) => ( 106600649559 )
          • TetherToken.transfer( _to=0xf6d1B70718596F14870079dCc7da881C753563F5, _value=137767042 )
            File 1 of 3: ERC1967Proxy
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)
            pragma solidity ^0.8.0;
            import "../utils/Context.sol";
            /**
             * @dev Contract module which provides a basic access control mechanism, where
             * there is an account (an owner) that can be granted exclusive access to
             * specific functions.
             *
             * By default, the owner account will be the one that deploys the contract. This
             * can later be changed with {transferOwnership}.
             *
             * This module is used through inheritance. It will make available the modifier
             * `onlyOwner`, which can be applied to your functions to restrict their use to
             * the owner.
             */
            abstract contract Ownable is Context {
                address private _owner;
                event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
                /**
                 * @dev Initializes the contract setting the deployer as the initial owner.
                 */
                constructor() {
                    _transferOwnership(_msgSender());
                }
                /**
                 * @dev Throws if called by any account other than the owner.
                 */
                modifier onlyOwner() {
                    _checkOwner();
                    _;
                }
                /**
                 * @dev Returns the address of the current owner.
                 */
                function owner() public view virtual returns (address) {
                    return _owner;
                }
                /**
                 * @dev Throws if the sender is not the owner.
                 */
                function _checkOwner() internal view virtual {
                    require(owner() == _msgSender(), "Ownable: caller is not the owner");
                }
                /**
                 * @dev Leaves the contract without owner. It will not be possible to call
                 * `onlyOwner` functions anymore. Can only be called by the current owner.
                 *
                 * NOTE: Renouncing ownership will leave the contract without an owner,
                 * thereby removing any functionality that is only available to the owner.
                 */
                function renounceOwnership() public virtual onlyOwner {
                    _transferOwnership(address(0));
                }
                /**
                 * @dev Transfers ownership of the contract to a new account (`newOwner`).
                 * Can only be called by the current owner.
                 */
                function transferOwnership(address newOwner) public virtual onlyOwner {
                    require(newOwner != address(0), "Ownable: new owner is the zero address");
                    _transferOwnership(newOwner);
                }
                /**
                 * @dev Transfers ownership of the contract to a new account (`newOwner`).
                 * Internal function without access restriction.
                 */
                function _transferOwnership(address newOwner) internal virtual {
                    address oldOwner = _owner;
                    _owner = newOwner;
                    emit OwnershipTransferred(oldOwner, newOwner);
                }
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.5.0) (interfaces/draft-IERC1822.sol)
            pragma solidity ^0.8.0;
            /**
             * @dev ERC1822: Universal Upgradeable Proxy Standard (UUPS) documents a method for upgradeability through a simplified
             * proxy whose upgrades are fully controlled by the current implementation.
             */
            interface IERC1822Proxiable {
                /**
                 * @dev Returns the storage slot that the proxiable contract assumes is being used to store the implementation
                 * address.
                 *
                 * IMPORTANT: A proxy pointing at a proxiable contract should not be considered proxiable itself, because this risks
                 * bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this
                 * function revert if invoked through a proxy.
                 */
                function proxiableUUID() external view returns (bytes32);
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.8.3) (interfaces/IERC1967.sol)
            pragma solidity ^0.8.0;
            /**
             * @dev ERC-1967: Proxy Storage Slots. This interface contains the events defined in the ERC.
             *
             * _Available since v4.9._
             */
            interface IERC1967 {
                /**
                 * @dev Emitted when the implementation is upgraded.
                 */
                event Upgraded(address indexed implementation);
                /**
                 * @dev Emitted when the admin account has changed.
                 */
                event AdminChanged(address previousAdmin, address newAdmin);
                /**
                 * @dev Emitted when the beacon is changed.
                 */
                event BeaconUpgraded(address indexed beacon);
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.7.0) (proxy/beacon/BeaconProxy.sol)
            pragma solidity ^0.8.0;
            import "./IBeacon.sol";
            import "../Proxy.sol";
            import "../ERC1967/ERC1967Upgrade.sol";
            /**
             * @dev This contract implements a proxy that gets the implementation address for each call from an {UpgradeableBeacon}.
             *
             * The beacon address is stored in storage slot `uint256(keccak256('eip1967.proxy.beacon')) - 1`, so that it doesn't
             * conflict with the storage layout of the implementation behind the proxy.
             *
             * _Available since v3.4._
             */
            contract BeaconProxy is Proxy, ERC1967Upgrade {
                /**
                 * @dev Initializes the proxy with `beacon`.
                 *
                 * If `data` is nonempty, it's used as data in a delegate call to the implementation returned by the beacon. This
                 * will typically be an encoded function call, and allows initializing the storage of the proxy like a Solidity
                 * constructor.
                 *
                 * Requirements:
                 *
                 * - `beacon` must be a contract with the interface {IBeacon}.
                 */
                constructor(address beacon, bytes memory data) payable {
                    _upgradeBeaconToAndCall(beacon, data, false);
                }
                /**
                 * @dev Returns the current beacon address.
                 */
                function _beacon() internal view virtual returns (address) {
                    return _getBeacon();
                }
                /**
                 * @dev Returns the current implementation address of the associated beacon.
                 */
                function _implementation() internal view virtual override returns (address) {
                    return IBeacon(_getBeacon()).implementation();
                }
                /**
                 * @dev Changes the proxy to use a new beacon. Deprecated: see {_upgradeBeaconToAndCall}.
                 *
                 * If `data` is nonempty, it's used as data in a delegate call to the implementation returned by the beacon.
                 *
                 * Requirements:
                 *
                 * - `beacon` must be a contract.
                 * - The implementation returned by `beacon` must be a contract.
                 */
                function _setBeacon(address beacon, bytes memory data) internal virtual {
                    _upgradeBeaconToAndCall(beacon, data, false);
                }
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts v4.4.1 (proxy/beacon/IBeacon.sol)
            pragma solidity ^0.8.0;
            /**
             * @dev This is the interface that {BeaconProxy} expects of its beacon.
             */
            interface IBeacon {
                /**
                 * @dev Must return an address that can be used as a delegate call target.
                 *
                 * {BeaconProxy} will check that this address is a contract.
                 */
                function implementation() external view returns (address);
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts v4.4.1 (proxy/beacon/UpgradeableBeacon.sol)
            pragma solidity ^0.8.0;
            import "./IBeacon.sol";
            import "../../access/Ownable.sol";
            import "../../utils/Address.sol";
            /**
             * @dev This contract is used in conjunction with one or more instances of {BeaconProxy} to determine their
             * implementation contract, which is where they will delegate all function calls.
             *
             * An owner is able to change the implementation the beacon points to, thus upgrading the proxies that use this beacon.
             */
            contract UpgradeableBeacon is IBeacon, Ownable {
                address private _implementation;
                /**
                 * @dev Emitted when the implementation returned by the beacon is changed.
                 */
                event Upgraded(address indexed implementation);
                /**
                 * @dev Sets the address of the initial implementation, and the deployer account as the owner who can upgrade the
                 * beacon.
                 */
                constructor(address implementation_) {
                    _setImplementation(implementation_);
                }
                /**
                 * @dev Returns the current implementation address.
                 */
                function implementation() public view virtual override returns (address) {
                    return _implementation;
                }
                /**
                 * @dev Upgrades the beacon to a new implementation.
                 *
                 * Emits an {Upgraded} event.
                 *
                 * Requirements:
                 *
                 * - msg.sender must be the owner of the contract.
                 * - `newImplementation` must be a contract.
                 */
                function upgradeTo(address newImplementation) public virtual onlyOwner {
                    _setImplementation(newImplementation);
                    emit Upgraded(newImplementation);
                }
                /**
                 * @dev Sets the implementation contract address for this beacon
                 *
                 * Requirements:
                 *
                 * - `newImplementation` must be a contract.
                 */
                function _setImplementation(address newImplementation) private {
                    require(Address.isContract(newImplementation), "UpgradeableBeacon: implementation is not a contract");
                    _implementation = newImplementation;
                }
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.7.0) (proxy/ERC1967/ERC1967Proxy.sol)
            pragma solidity ^0.8.0;
            import "../Proxy.sol";
            import "./ERC1967Upgrade.sol";
            /**
             * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
             * implementation address that can be changed. This address is stored in storage in the location specified by
             * https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the
             * implementation behind the proxy.
             */
            contract ERC1967Proxy is Proxy, ERC1967Upgrade {
                /**
                 * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`.
                 *
                 * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded
                 * function call, and allows initializing the storage of the proxy like a Solidity constructor.
                 */
                constructor(address _logic, bytes memory _data) payable {
                    _upgradeToAndCall(_logic, _data, false);
                }
                /**
                 * @dev Returns the current implementation address.
                 */
                function _implementation() internal view virtual override returns (address impl) {
                    return ERC1967Upgrade._getImplementation();
                }
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.8.3) (proxy/ERC1967/ERC1967Upgrade.sol)
            pragma solidity ^0.8.2;
            import "../beacon/IBeacon.sol";
            import "../../interfaces/IERC1967.sol";
            import "../../interfaces/draft-IERC1822.sol";
            import "../../utils/Address.sol";
            import "../../utils/StorageSlot.sol";
            /**
             * @dev This abstract contract provides getters and event emitting update functions for
             * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
             *
             * _Available since v4.1._
             *
             * @custom:oz-upgrades-unsafe-allow delegatecall
             */
            abstract contract ERC1967Upgrade is IERC1967 {
                // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
                bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;
                /**
                 * @dev Storage slot with the address of the current implementation.
                 * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
                 * validated in the constructor.
                 */
                bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
                /**
                 * @dev Returns the current implementation address.
                 */
                function _getImplementation() internal view returns (address) {
                    return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
                }
                /**
                 * @dev Stores a new address in the EIP1967 implementation slot.
                 */
                function _setImplementation(address newImplementation) private {
                    require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
                    StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
                }
                /**
                 * @dev Perform implementation upgrade
                 *
                 * Emits an {Upgraded} event.
                 */
                function _upgradeTo(address newImplementation) internal {
                    _setImplementation(newImplementation);
                    emit Upgraded(newImplementation);
                }
                /**
                 * @dev Perform implementation upgrade with additional setup call.
                 *
                 * Emits an {Upgraded} event.
                 */
                function _upgradeToAndCall(
                    address newImplementation,
                    bytes memory data,
                    bool forceCall
                ) internal {
                    _upgradeTo(newImplementation);
                    if (data.length > 0 || forceCall) {
                        Address.functionDelegateCall(newImplementation, data);
                    }
                }
                /**
                 * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
                 *
                 * Emits an {Upgraded} event.
                 */
                function _upgradeToAndCallUUPS(
                    address newImplementation,
                    bytes memory data,
                    bool forceCall
                ) internal {
                    // Upgrades from old implementations will perform a rollback test. This test requires the new
                    // implementation to upgrade back to the old, non-ERC1822 compliant, implementation. Removing
                    // this special case will break upgrade paths from old UUPS implementation to new ones.
                    if (StorageSlot.getBooleanSlot(_ROLLBACK_SLOT).value) {
                        _setImplementation(newImplementation);
                    } else {
                        try IERC1822Proxiable(newImplementation).proxiableUUID() returns (bytes32 slot) {
                            require(slot == _IMPLEMENTATION_SLOT, "ERC1967Upgrade: unsupported proxiableUUID");
                        } catch {
                            revert("ERC1967Upgrade: new implementation is not UUPS");
                        }
                        _upgradeToAndCall(newImplementation, data, forceCall);
                    }
                }
                /**
                 * @dev Storage slot with the admin of the contract.
                 * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
                 * validated in the constructor.
                 */
                bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
                /**
                 * @dev Returns the current admin.
                 */
                function _getAdmin() internal view returns (address) {
                    return StorageSlot.getAddressSlot(_ADMIN_SLOT).value;
                }
                /**
                 * @dev Stores a new address in the EIP1967 admin slot.
                 */
                function _setAdmin(address newAdmin) private {
                    require(newAdmin != address(0), "ERC1967: new admin is the zero address");
                    StorageSlot.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
                }
                /**
                 * @dev Changes the admin of the proxy.
                 *
                 * Emits an {AdminChanged} event.
                 */
                function _changeAdmin(address newAdmin) internal {
                    emit AdminChanged(_getAdmin(), newAdmin);
                    _setAdmin(newAdmin);
                }
                /**
                 * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
                 * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
                 */
                bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
                /**
                 * @dev Returns the current beacon.
                 */
                function _getBeacon() internal view returns (address) {
                    return StorageSlot.getAddressSlot(_BEACON_SLOT).value;
                }
                /**
                 * @dev Stores a new beacon in the EIP1967 beacon slot.
                 */
                function _setBeacon(address newBeacon) private {
                    require(Address.isContract(newBeacon), "ERC1967: new beacon is not a contract");
                    require(
                        Address.isContract(IBeacon(newBeacon).implementation()),
                        "ERC1967: beacon implementation is not a contract"
                    );
                    StorageSlot.getAddressSlot(_BEACON_SLOT).value = newBeacon;
                }
                /**
                 * @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
                 * not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
                 *
                 * Emits a {BeaconUpgraded} event.
                 */
                function _upgradeBeaconToAndCall(
                    address newBeacon,
                    bytes memory data,
                    bool forceCall
                ) internal {
                    _setBeacon(newBeacon);
                    emit BeaconUpgraded(newBeacon);
                    if (data.length > 0 || forceCall) {
                        Address.functionDelegateCall(IBeacon(newBeacon).implementation(), data);
                    }
                }
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.6.0) (proxy/Proxy.sol)
            pragma solidity ^0.8.0;
            /**
             * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
             * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
             * be specified by overriding the virtual {_implementation} function.
             *
             * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
             * different contract through the {_delegate} function.
             *
             * The success and return data of the delegated call will be returned back to the caller of the proxy.
             */
            abstract contract Proxy {
                /**
                 * @dev Delegates the current call to `implementation`.
                 *
                 * This function does not return to its internal call site, it will return directly to the external caller.
                 */
                function _delegate(address implementation) internal virtual {
                    assembly {
                        // Copy msg.data. We take full control of memory in this inline assembly
                        // block because it will not return to Solidity code. We overwrite the
                        // Solidity scratch pad at memory position 0.
                        calldatacopy(0, 0, calldatasize())
                        // Call the implementation.
                        // out and outsize are 0 because we don't know the size yet.
                        let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)
                        // Copy the returned data.
                        returndatacopy(0, 0, returndatasize())
                        switch result
                        // delegatecall returns 0 on error.
                        case 0 {
                            revert(0, returndatasize())
                        }
                        default {
                            return(0, returndatasize())
                        }
                    }
                }
                /**
                 * @dev This is a virtual function that should be overridden so it returns the address to which the fallback function
                 * and {_fallback} should delegate.
                 */
                function _implementation() internal view virtual returns (address);
                /**
                 * @dev Delegates the current call to the address returned by `_implementation()`.
                 *
                 * This function does not return to its internal call site, it will return directly to the external caller.
                 */
                function _fallback() internal virtual {
                    _beforeFallback();
                    _delegate(_implementation());
                }
                /**
                 * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
                 * function in the contract matches the call data.
                 */
                fallback() external payable virtual {
                    _fallback();
                }
                /**
                 * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
                 * is empty.
                 */
                receive() external payable virtual {
                    _fallback();
                }
                /**
                 * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
                 * call, or as part of the Solidity `fallback` or `receive` functions.
                 *
                 * If overridden should call `super._beforeFallback()`.
                 */
                function _beforeFallback() internal virtual {}
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.8.3) (proxy/transparent/ProxyAdmin.sol)
            pragma solidity ^0.8.0;
            import "./TransparentUpgradeableProxy.sol";
            import "../../access/Ownable.sol";
            /**
             * @dev This is an auxiliary contract meant to be assigned as the admin of a {TransparentUpgradeableProxy}. For an
             * explanation of why you would want to use this see the documentation for {TransparentUpgradeableProxy}.
             */
            contract ProxyAdmin is Ownable {
                /**
                 * @dev Returns the current implementation of `proxy`.
                 *
                 * Requirements:
                 *
                 * - This contract must be the admin of `proxy`.
                 */
                function getProxyImplementation(ITransparentUpgradeableProxy proxy) public view virtual returns (address) {
                    // We need to manually run the static call since the getter cannot be flagged as view
                    // bytes4(keccak256("implementation()")) == 0x5c60da1b
                    (bool success, bytes memory returndata) = address(proxy).staticcall(hex"5c60da1b");
                    require(success);
                    return abi.decode(returndata, (address));
                }
                /**
                 * @dev Returns the current admin of `proxy`.
                 *
                 * Requirements:
                 *
                 * - This contract must be the admin of `proxy`.
                 */
                function getProxyAdmin(ITransparentUpgradeableProxy proxy) public view virtual returns (address) {
                    // We need to manually run the static call since the getter cannot be flagged as view
                    // bytes4(keccak256("admin()")) == 0xf851a440
                    (bool success, bytes memory returndata) = address(proxy).staticcall(hex"f851a440");
                    require(success);
                    return abi.decode(returndata, (address));
                }
                /**
                 * @dev Changes the admin of `proxy` to `newAdmin`.
                 *
                 * Requirements:
                 *
                 * - This contract must be the current admin of `proxy`.
                 */
                function changeProxyAdmin(ITransparentUpgradeableProxy proxy, address newAdmin) public virtual onlyOwner {
                    proxy.changeAdmin(newAdmin);
                }
                /**
                 * @dev Upgrades `proxy` to `implementation`. See {TransparentUpgradeableProxy-upgradeTo}.
                 *
                 * Requirements:
                 *
                 * - This contract must be the admin of `proxy`.
                 */
                function upgrade(ITransparentUpgradeableProxy proxy, address implementation) public virtual onlyOwner {
                    proxy.upgradeTo(implementation);
                }
                /**
                 * @dev Upgrades `proxy` to `implementation` and calls a function on the new implementation. See
                 * {TransparentUpgradeableProxy-upgradeToAndCall}.
                 *
                 * Requirements:
                 *
                 * - This contract must be the admin of `proxy`.
                 */
                function upgradeAndCall(
                    ITransparentUpgradeableProxy proxy,
                    address implementation,
                    bytes memory data
                ) public payable virtual onlyOwner {
                    proxy.upgradeToAndCall{value: msg.value}(implementation, data);
                }
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.8.3) (proxy/transparent/TransparentUpgradeableProxy.sol)
            pragma solidity ^0.8.0;
            import "../ERC1967/ERC1967Proxy.sol";
            /**
             * @dev Interface for {TransparentUpgradeableProxy}. In order to implement transparency, {TransparentUpgradeableProxy}
             * does not implement this interface directly, and some of its functions are implemented by an internal dispatch
             * mechanism. The compiler is unaware that these functions are implemented by {TransparentUpgradeableProxy} and will not
             * include them in the ABI so this interface must be used to interact with it.
             */
            interface ITransparentUpgradeableProxy is IERC1967 {
                function admin() external view returns (address);
                function implementation() external view returns (address);
                function changeAdmin(address) external;
                function upgradeTo(address) external;
                function upgradeToAndCall(address, bytes memory) external payable;
            }
            /**
             * @dev This contract implements a proxy that is upgradeable by an admin.
             *
             * To avoid https://medium.com/nomic-labs-blog/malicious-backdoors-in-ethereum-proxies-62629adf3357[proxy selector
             * clashing], which can potentially be used in an attack, this contract uses the
             * https://blog.openzeppelin.com/the-transparent-proxy-pattern/[transparent proxy pattern]. This pattern implies two
             * things that go hand in hand:
             *
             * 1. If any account other than the admin calls the proxy, the call will be forwarded to the implementation, even if
             * that call matches one of the admin functions exposed by the proxy itself.
             * 2. If the admin calls the proxy, it can access the admin functions, but its calls will never be forwarded to the
             * implementation. If the admin tries to call a function on the implementation it will fail with an error that says
             * "admin cannot fallback to proxy target".
             *
             * These properties mean that the admin account can only be used for admin actions like upgrading the proxy or changing
             * the admin, so it's best if it's a dedicated account that is not used for anything else. This will avoid headaches due
             * to sudden errors when trying to call a function from the proxy implementation.
             *
             * Our recommendation is for the dedicated account to be an instance of the {ProxyAdmin} contract. If set up this way,
             * you should think of the `ProxyAdmin` instance as the real administrative interface of your proxy.
             *
             * NOTE: The real interface of this proxy is that defined in `ITransparentUpgradeableProxy`. This contract does not
             * inherit from that interface, and instead the admin functions are implicitly implemented using a custom dispatch
             * mechanism in `_fallback`. Consequently, the compiler will not produce an ABI for this contract. This is necessary to
             * fully implement transparency without decoding reverts caused by selector clashes between the proxy and the
             * implementation.
             *
             * WARNING: It is not recommended to extend this contract to add additional external functions. If you do so, the compiler
             * will not check that there are no selector conflicts, due to the note above. A selector clash between any new function
             * and the functions declared in {ITransparentUpgradeableProxy} will be resolved in favor of the new one. This could
             * render the admin operations inaccessible, which could prevent upgradeability. Transparency may also be compromised.
             */
            contract TransparentUpgradeableProxy is ERC1967Proxy {
                /**
                 * @dev Initializes an upgradeable proxy managed by `_admin`, backed by the implementation at `_logic`, and
                 * optionally initialized with `_data` as explained in {ERC1967Proxy-constructor}.
                 */
                constructor(
                    address _logic,
                    address admin_,
                    bytes memory _data
                ) payable ERC1967Proxy(_logic, _data) {
                    _changeAdmin(admin_);
                }
                /**
                 * @dev Modifier used internally that will delegate the call to the implementation unless the sender is the admin.
                 *
                 * CAUTION: This modifier is deprecated, as it could cause issues if the modified function has arguments, and the
                 * implementation provides a function with the same selector.
                 */
                modifier ifAdmin() {
                    if (msg.sender == _getAdmin()) {
                        _;
                    } else {
                        _fallback();
                    }
                }
                /**
                 * @dev If caller is the admin process the call internally, otherwise transparently fallback to the proxy behavior
                 */
                function _fallback() internal virtual override {
                    if (msg.sender == _getAdmin()) {
                        bytes memory ret;
                        bytes4 selector = msg.sig;
                        if (selector == ITransparentUpgradeableProxy.upgradeTo.selector) {
                            ret = _dispatchUpgradeTo();
                        } else if (selector == ITransparentUpgradeableProxy.upgradeToAndCall.selector) {
                            ret = _dispatchUpgradeToAndCall();
                        } else if (selector == ITransparentUpgradeableProxy.changeAdmin.selector) {
                            ret = _dispatchChangeAdmin();
                        } else if (selector == ITransparentUpgradeableProxy.admin.selector) {
                            ret = _dispatchAdmin();
                        } else if (selector == ITransparentUpgradeableProxy.implementation.selector) {
                            ret = _dispatchImplementation();
                        } else {
                            revert("TransparentUpgradeableProxy: admin cannot fallback to proxy target");
                        }
                        assembly {
                            return(add(ret, 0x20), mload(ret))
                        }
                    } else {
                        super._fallback();
                    }
                }
                /**
                 * @dev Returns the current admin.
                 *
                 * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
                 * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
                 * `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
                 */
                function _dispatchAdmin() private returns (bytes memory) {
                    _requireZeroValue();
                    address admin = _getAdmin();
                    return abi.encode(admin);
                }
                /**
                 * @dev Returns the current implementation.
                 *
                 * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
                 * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
                 * `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
                 */
                function _dispatchImplementation() private returns (bytes memory) {
                    _requireZeroValue();
                    address implementation = _implementation();
                    return abi.encode(implementation);
                }
                /**
                 * @dev Changes the admin of the proxy.
                 *
                 * Emits an {AdminChanged} event.
                 */
                function _dispatchChangeAdmin() private returns (bytes memory) {
                    _requireZeroValue();
                    address newAdmin = abi.decode(msg.data[4:], (address));
                    _changeAdmin(newAdmin);
                    return "";
                }
                /**
                 * @dev Upgrade the implementation of the proxy.
                 */
                function _dispatchUpgradeTo() private returns (bytes memory) {
                    _requireZeroValue();
                    address newImplementation = abi.decode(msg.data[4:], (address));
                    _upgradeToAndCall(newImplementation, bytes(""), false);
                    return "";
                }
                /**
                 * @dev Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
                 * by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
                 * proxied contract.
                 */
                function _dispatchUpgradeToAndCall() private returns (bytes memory) {
                    (address newImplementation, bytes memory data) = abi.decode(msg.data[4:], (address, bytes));
                    _upgradeToAndCall(newImplementation, data, true);
                    return "";
                }
                /**
                 * @dev Returns the current admin.
                 */
                function _admin() internal view virtual returns (address) {
                    return _getAdmin();
                }
                /**
                 * @dev To keep this contract fully transparent, all `ifAdmin` functions must be payable. This helper is here to
                 * emulate some proxy functions being non-payable while still allowing value to pass through.
                 */
                function _requireZeroValue() private {
                    require(msg.value == 0);
                }
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol)
            pragma solidity ^0.8.1;
            /**
             * @dev Collection of functions related to the address type
             */
            library Address {
                /**
                 * @dev Returns true if `account` is a contract.
                 *
                 * [IMPORTANT]
                 * ====
                 * It is unsafe to assume that an address for which this function returns
                 * false is an externally-owned account (EOA) and not a contract.
                 *
                 * Among others, `isContract` will return false for the following
                 * types of addresses:
                 *
                 *  - an externally-owned account
                 *  - a contract in construction
                 *  - an address where a contract will be created
                 *  - an address where a contract lived, but was destroyed
                 * ====
                 *
                 * [IMPORTANT]
                 * ====
                 * You shouldn't rely on `isContract` to protect against flash loan attacks!
                 *
                 * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
                 * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
                 * constructor.
                 * ====
                 */
                function isContract(address account) internal view returns (bool) {
                    // This method relies on extcodesize/address.code.length, which returns 0
                    // for contracts in construction, since the code is only stored at the end
                    // of the constructor execution.
                    return account.code.length > 0;
                }
                /**
                 * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
                 * `recipient`, forwarding all available gas and reverting on errors.
                 *
                 * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
                 * of certain opcodes, possibly making contracts go over the 2300 gas limit
                 * imposed by `transfer`, making them unable to receive funds via
                 * `transfer`. {sendValue} removes this limitation.
                 *
                 * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
                 *
                 * IMPORTANT: because control is transferred to `recipient`, care must be
                 * taken to not create reentrancy vulnerabilities. Consider using
                 * {ReentrancyGuard} or the
                 * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
                 */
                function sendValue(address payable recipient, uint256 amount) internal {
                    require(address(this).balance >= amount, "Address: insufficient balance");
                    (bool success, ) = recipient.call{value: amount}("");
                    require(success, "Address: unable to send value, recipient may have reverted");
                }
                /**
                 * @dev Performs a Solidity function call using a low level `call`. A
                 * plain `call` is an unsafe replacement for a function call: use this
                 * function instead.
                 *
                 * If `target` reverts with a revert reason, it is bubbled up by this
                 * function (like regular Solidity function calls).
                 *
                 * Returns the raw returned data. To convert to the expected return value,
                 * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
                 *
                 * Requirements:
                 *
                 * - `target` must be a contract.
                 * - calling `target` with `data` must not revert.
                 *
                 * _Available since v3.1._
                 */
                function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                    return functionCallWithValue(target, data, 0, "Address: low-level call failed");
                }
                /**
                 * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
                 * `errorMessage` as a fallback revert reason when `target` reverts.
                 *
                 * _Available since v3.1._
                 */
                function functionCall(
                    address target,
                    bytes memory data,
                    string memory errorMessage
                ) internal returns (bytes memory) {
                    return functionCallWithValue(target, data, 0, errorMessage);
                }
                /**
                 * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                 * but also transferring `value` wei to `target`.
                 *
                 * Requirements:
                 *
                 * - the calling contract must have an ETH balance of at least `value`.
                 * - the called Solidity function must be `payable`.
                 *
                 * _Available since v3.1._
                 */
                function functionCallWithValue(
                    address target,
                    bytes memory data,
                    uint256 value
                ) internal returns (bytes memory) {
                    return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
                }
                /**
                 * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
                 * with `errorMessage` as a fallback revert reason when `target` reverts.
                 *
                 * _Available since v3.1._
                 */
                function functionCallWithValue(
                    address target,
                    bytes memory data,
                    uint256 value,
                    string memory errorMessage
                ) internal returns (bytes memory) {
                    require(address(this).balance >= value, "Address: insufficient balance for call");
                    (bool success, bytes memory returndata) = target.call{value: value}(data);
                    return verifyCallResultFromTarget(target, success, returndata, errorMessage);
                }
                /**
                 * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                 * but performing a static call.
                 *
                 * _Available since v3.3._
                 */
                function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                    return functionStaticCall(target, data, "Address: low-level static call failed");
                }
                /**
                 * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                 * but performing a static call.
                 *
                 * _Available since v3.3._
                 */
                function functionStaticCall(
                    address target,
                    bytes memory data,
                    string memory errorMessage
                ) internal view returns (bytes memory) {
                    (bool success, bytes memory returndata) = target.staticcall(data);
                    return verifyCallResultFromTarget(target, success, returndata, errorMessage);
                }
                /**
                 * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                 * but performing a delegate call.
                 *
                 * _Available since v3.4._
                 */
                function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
                    return functionDelegateCall(target, data, "Address: low-level delegate call failed");
                }
                /**
                 * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                 * but performing a delegate call.
                 *
                 * _Available since v3.4._
                 */
                function functionDelegateCall(
                    address target,
                    bytes memory data,
                    string memory errorMessage
                ) internal returns (bytes memory) {
                    (bool success, bytes memory returndata) = target.delegatecall(data);
                    return verifyCallResultFromTarget(target, success, returndata, errorMessage);
                }
                /**
                 * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
                 * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
                 *
                 * _Available since v4.8._
                 */
                function verifyCallResultFromTarget(
                    address target,
                    bool success,
                    bytes memory returndata,
                    string memory errorMessage
                ) internal view returns (bytes memory) {
                    if (success) {
                        if (returndata.length == 0) {
                            // only check isContract if the call was successful and the return data is empty
                            // otherwise we already know that it was a contract
                            require(isContract(target), "Address: call to non-contract");
                        }
                        return returndata;
                    } else {
                        _revert(returndata, errorMessage);
                    }
                }
                /**
                 * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
                 * revert reason or using the provided one.
                 *
                 * _Available since v4.3._
                 */
                function verifyCallResult(
                    bool success,
                    bytes memory returndata,
                    string memory errorMessage
                ) internal pure returns (bytes memory) {
                    if (success) {
                        return returndata;
                    } else {
                        _revert(returndata, errorMessage);
                    }
                }
                function _revert(bytes memory returndata, string memory errorMessage) private pure {
                    // Look for revert reason and bubble it up if present
                    if (returndata.length > 0) {
                        // The easiest way to bubble the revert reason is using memory via assembly
                        /// @solidity memory-safe-assembly
                        assembly {
                            let returndata_size := mload(returndata)
                            revert(add(32, returndata), returndata_size)
                        }
                    } else {
                        revert(errorMessage);
                    }
                }
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
            pragma solidity ^0.8.0;
            /**
             * @dev Provides information about the current execution context, including the
             * sender of the transaction and its data. While these are generally available
             * via msg.sender and msg.data, they should not be accessed in such a direct
             * manner, since when dealing with meta-transactions the account sending and
             * paying for execution may not be the actual sender (as far as an application
             * is concerned).
             *
             * This contract is only required for intermediate, library-like contracts.
             */
            abstract contract Context {
                function _msgSender() internal view virtual returns (address) {
                    return msg.sender;
                }
                function _msgData() internal view virtual returns (bytes calldata) {
                    return msg.data;
                }
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.7.0) (utils/StorageSlot.sol)
            pragma solidity ^0.8.0;
            /**
             * @dev Library for reading and writing primitive types to specific storage slots.
             *
             * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
             * This library helps with reading and writing to such slots without the need for inline assembly.
             *
             * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
             *
             * Example usage to set ERC1967 implementation slot:
             * ```
             * contract ERC1967 {
             *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
             *
             *     function _getImplementation() internal view returns (address) {
             *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
             *     }
             *
             *     function _setImplementation(address newImplementation) internal {
             *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
             *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
             *     }
             * }
             * ```
             *
             * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
             */
            library StorageSlot {
                struct AddressSlot {
                    address value;
                }
                struct BooleanSlot {
                    bool value;
                }
                struct Bytes32Slot {
                    bytes32 value;
                }
                struct Uint256Slot {
                    uint256 value;
                }
                /**
                 * @dev Returns an `AddressSlot` with member `value` located at `slot`.
                 */
                function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
                    /// @solidity memory-safe-assembly
                    assembly {
                        r.slot := slot
                    }
                }
                /**
                 * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
                 */
                function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
                    /// @solidity memory-safe-assembly
                    assembly {
                        r.slot := slot
                    }
                }
                /**
                 * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
                 */
                function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
                    /// @solidity memory-safe-assembly
                    assembly {
                        r.slot := slot
                    }
                }
                /**
                 * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
                 */
                function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
                    /// @solidity memory-safe-assembly
                    assembly {
                        r.slot := slot
                    }
                }
            }
            

            File 2 of 3: TetherToken
            pragma solidity ^0.4.17;
            
            /**
             * @title SafeMath
             * @dev Math operations with safety checks that throw on error
             */
            library SafeMath {
                function mul(uint256 a, uint256 b) internal pure returns (uint256) {
                    if (a == 0) {
                        return 0;
                    }
                    uint256 c = a * b;
                    assert(c / a == b);
                    return c;
                }
            
                function div(uint256 a, uint256 b) internal pure returns (uint256) {
                    // assert(b > 0); // Solidity automatically throws when dividing by 0
                    uint256 c = a / b;
                    // assert(a == b * c + a % b); // There is no case in which this doesn't hold
                    return c;
                }
            
                function sub(uint256 a, uint256 b) internal pure returns (uint256) {
                    assert(b <= a);
                    return a - b;
                }
            
                function add(uint256 a, uint256 b) internal pure returns (uint256) {
                    uint256 c = a + b;
                    assert(c >= a);
                    return c;
                }
            }
            
            /**
             * @title Ownable
             * @dev The Ownable contract has an owner address, and provides basic authorization control
             * functions, this simplifies the implementation of "user permissions".
             */
            contract Ownable {
                address public owner;
            
                /**
                  * @dev The Ownable constructor sets the original `owner` of the contract to the sender
                  * account.
                  */
                function Ownable() public {
                    owner = msg.sender;
                }
            
                /**
                  * @dev Throws if called by any account other than the owner.
                  */
                modifier onlyOwner() {
                    require(msg.sender == 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) public onlyOwner {
                    if (newOwner != address(0)) {
                        owner = newOwner;
                    }
                }
            
            }
            
            /**
             * @title ERC20Basic
             * @dev Simpler version of ERC20 interface
             * @dev see https://github.com/ethereum/EIPs/issues/20
             */
            contract ERC20Basic {
                uint public _totalSupply;
                function totalSupply() public constant returns (uint);
                function balanceOf(address who) public constant returns (uint);
                function transfer(address to, uint value) public;
                event Transfer(address indexed from, address indexed to, uint value);
            }
            
            /**
             * @title ERC20 interface
             * @dev see https://github.com/ethereum/EIPs/issues/20
             */
            contract ERC20 is ERC20Basic {
                function allowance(address owner, address spender) public constant returns (uint);
                function transferFrom(address from, address to, uint value) public;
                function approve(address spender, uint value) public;
                event Approval(address indexed owner, address indexed spender, uint value);
            }
            
            /**
             * @title Basic token
             * @dev Basic version of StandardToken, with no allowances.
             */
            contract BasicToken is Ownable, ERC20Basic {
                using SafeMath for uint;
            
                mapping(address => uint) public balances;
            
                // additional variables for use if transaction fees ever became necessary
                uint public basisPointsRate = 0;
                uint public maximumFee = 0;
            
                /**
                * @dev Fix for the ERC20 short address attack.
                */
                modifier onlyPayloadSize(uint size) {
                    require(!(msg.data.length < size + 4));
                    _;
                }
            
                /**
                * @dev transfer token for a specified address
                * @param _to The address to transfer to.
                * @param _value The amount to be transferred.
                */
                function transfer(address _to, uint _value) public onlyPayloadSize(2 * 32) {
                    uint fee = (_value.mul(basisPointsRate)).div(10000);
                    if (fee > maximumFee) {
                        fee = maximumFee;
                    }
                    uint sendAmount = _value.sub(fee);
                    balances[msg.sender] = balances[msg.sender].sub(_value);
                    balances[_to] = balances[_to].add(sendAmount);
                    if (fee > 0) {
                        balances[owner] = balances[owner].add(fee);
                        Transfer(msg.sender, owner, fee);
                    }
                    Transfer(msg.sender, _to, sendAmount);
                }
            
                /**
                * @dev Gets the balance of the specified address.
                * @param _owner The address to query the the balance of.
                * @return An uint representing the amount owned by the passed address.
                */
                function balanceOf(address _owner) public constant returns (uint balance) {
                    return balances[_owner];
                }
            
            }
            
            /**
             * @title Standard ERC20 token
             *
             * @dev Implementation of the basic standard token.
             * @dev https://github.com/ethereum/EIPs/issues/20
             * @dev Based oncode by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
             */
            contract StandardToken is BasicToken, ERC20 {
            
                mapping (address => mapping (address => uint)) public allowed;
            
                uint public constant MAX_UINT = 2**256 - 1;
            
                /**
                * @dev Transfer tokens from one address to another
                * @param _from address The address which you want to send tokens from
                * @param _to address The address which you want to transfer to
                * @param _value uint the amount of tokens to be transferred
                */
                function transferFrom(address _from, address _to, uint _value) public onlyPayloadSize(3 * 32) {
                    var _allowance = allowed[_from][msg.sender];
            
                    // Check is not needed because sub(_allowance, _value) will already throw if this condition is not met
                    // if (_value > _allowance) throw;
            
                    uint fee = (_value.mul(basisPointsRate)).div(10000);
                    if (fee > maximumFee) {
                        fee = maximumFee;
                    }
                    if (_allowance < MAX_UINT) {
                        allowed[_from][msg.sender] = _allowance.sub(_value);
                    }
                    uint sendAmount = _value.sub(fee);
                    balances[_from] = balances[_from].sub(_value);
                    balances[_to] = balances[_to].add(sendAmount);
                    if (fee > 0) {
                        balances[owner] = balances[owner].add(fee);
                        Transfer(_from, owner, fee);
                    }
                    Transfer(_from, _to, sendAmount);
                }
            
                /**
                * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
                * @param _spender The address which will spend the funds.
                * @param _value The amount of tokens to be spent.
                */
                function approve(address _spender, uint _value) public onlyPayloadSize(2 * 32) {
            
                    // To change the approve amount you first have to reduce the addresses`
                    //  allowance to zero by calling `approve(_spender, 0)` if it is not
                    //  already 0 to mitigate the race condition described here:
                    //  https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
                    require(!((_value != 0) && (allowed[msg.sender][_spender] != 0)));
            
                    allowed[msg.sender][_spender] = _value;
                    Approval(msg.sender, _spender, _value);
                }
            
                /**
                * @dev Function to check the amount of tokens than an owner allowed to a spender.
                * @param _owner address The address which owns the funds.
                * @param _spender address The address which will spend the funds.
                * @return A uint specifying the amount of tokens still available for the spender.
                */
                function allowance(address _owner, address _spender) public constant returns (uint remaining) {
                    return allowed[_owner][_spender];
                }
            
            }
            
            
            /**
             * @title Pausable
             * @dev Base contract which allows children to implement an emergency stop mechanism.
             */
            contract Pausable is Ownable {
              event Pause();
              event Unpause();
            
              bool public paused = false;
            
            
              /**
               * @dev Modifier to make a function callable only when the contract is not paused.
               */
              modifier whenNotPaused() {
                require(!paused);
                _;
              }
            
              /**
               * @dev Modifier to make a function callable only when the contract is paused.
               */
              modifier whenPaused() {
                require(paused);
                _;
              }
            
              /**
               * @dev called by the owner to pause, triggers stopped state
               */
              function pause() onlyOwner whenNotPaused public {
                paused = true;
                Pause();
              }
            
              /**
               * @dev called by the owner to unpause, returns to normal state
               */
              function unpause() onlyOwner whenPaused public {
                paused = false;
                Unpause();
              }
            }
            
            contract BlackList is Ownable, BasicToken {
            
                /////// Getters to allow the same blacklist to be used also by other contracts (including upgraded Tether) ///////
                function getBlackListStatus(address _maker) external constant returns (bool) {
                    return isBlackListed[_maker];
                }
            
                function getOwner() external constant returns (address) {
                    return owner;
                }
            
                mapping (address => bool) public isBlackListed;
                
                function addBlackList (address _evilUser) public onlyOwner {
                    isBlackListed[_evilUser] = true;
                    AddedBlackList(_evilUser);
                }
            
                function removeBlackList (address _clearedUser) public onlyOwner {
                    isBlackListed[_clearedUser] = false;
                    RemovedBlackList(_clearedUser);
                }
            
                function destroyBlackFunds (address _blackListedUser) public onlyOwner {
                    require(isBlackListed[_blackListedUser]);
                    uint dirtyFunds = balanceOf(_blackListedUser);
                    balances[_blackListedUser] = 0;
                    _totalSupply -= dirtyFunds;
                    DestroyedBlackFunds(_blackListedUser, dirtyFunds);
                }
            
                event DestroyedBlackFunds(address _blackListedUser, uint _balance);
            
                event AddedBlackList(address _user);
            
                event RemovedBlackList(address _user);
            
            }
            
            contract UpgradedStandardToken is StandardToken{
                // those methods are called by the legacy contract
                // and they must ensure msg.sender to be the contract address
                function transferByLegacy(address from, address to, uint value) public;
                function transferFromByLegacy(address sender, address from, address spender, uint value) public;
                function approveByLegacy(address from, address spender, uint value) public;
            }
            
            contract TetherToken is Pausable, StandardToken, BlackList {
            
                string public name;
                string public symbol;
                uint public decimals;
                address public upgradedAddress;
                bool public deprecated;
            
                //  The contract can be initialized with a number of tokens
                //  All the tokens are deposited to the owner address
                //
                // @param _balance Initial supply of the contract
                // @param _name Token Name
                // @param _symbol Token symbol
                // @param _decimals Token decimals
                function TetherToken(uint _initialSupply, string _name, string _symbol, uint _decimals) public {
                    _totalSupply = _initialSupply;
                    name = _name;
                    symbol = _symbol;
                    decimals = _decimals;
                    balances[owner] = _initialSupply;
                    deprecated = false;
                }
            
                // Forward ERC20 methods to upgraded contract if this one is deprecated
                function transfer(address _to, uint _value) public whenNotPaused {
                    require(!isBlackListed[msg.sender]);
                    if (deprecated) {
                        return UpgradedStandardToken(upgradedAddress).transferByLegacy(msg.sender, _to, _value);
                    } else {
                        return super.transfer(_to, _value);
                    }
                }
            
                // Forward ERC20 methods to upgraded contract if this one is deprecated
                function transferFrom(address _from, address _to, uint _value) public whenNotPaused {
                    require(!isBlackListed[_from]);
                    if (deprecated) {
                        return UpgradedStandardToken(upgradedAddress).transferFromByLegacy(msg.sender, _from, _to, _value);
                    } else {
                        return super.transferFrom(_from, _to, _value);
                    }
                }
            
                // Forward ERC20 methods to upgraded contract if this one is deprecated
                function balanceOf(address who) public constant returns (uint) {
                    if (deprecated) {
                        return UpgradedStandardToken(upgradedAddress).balanceOf(who);
                    } else {
                        return super.balanceOf(who);
                    }
                }
            
                // Forward ERC20 methods to upgraded contract if this one is deprecated
                function approve(address _spender, uint _value) public onlyPayloadSize(2 * 32) {
                    if (deprecated) {
                        return UpgradedStandardToken(upgradedAddress).approveByLegacy(msg.sender, _spender, _value);
                    } else {
                        return super.approve(_spender, _value);
                    }
                }
            
                // Forward ERC20 methods to upgraded contract if this one is deprecated
                function allowance(address _owner, address _spender) public constant returns (uint remaining) {
                    if (deprecated) {
                        return StandardToken(upgradedAddress).allowance(_owner, _spender);
                    } else {
                        return super.allowance(_owner, _spender);
                    }
                }
            
                // deprecate current contract in favour of a new one
                function deprecate(address _upgradedAddress) public onlyOwner {
                    deprecated = true;
                    upgradedAddress = _upgradedAddress;
                    Deprecate(_upgradedAddress);
                }
            
                // deprecate current contract if favour of a new one
                function totalSupply() public constant returns (uint) {
                    if (deprecated) {
                        return StandardToken(upgradedAddress).totalSupply();
                    } else {
                        return _totalSupply;
                    }
                }
            
                // Issue a new amount of tokens
                // these tokens are deposited into the owner address
                //
                // @param _amount Number of tokens to be issued
                function issue(uint amount) public onlyOwner {
                    require(_totalSupply + amount > _totalSupply);
                    require(balances[owner] + amount > balances[owner]);
            
                    balances[owner] += amount;
                    _totalSupply += amount;
                    Issue(amount);
                }
            
                // Redeem tokens.
                // These tokens are withdrawn from the owner address
                // if the balance must be enough to cover the redeem
                // or the call will fail.
                // @param _amount Number of tokens to be issued
                function redeem(uint amount) public onlyOwner {
                    require(_totalSupply >= amount);
                    require(balances[owner] >= amount);
            
                    _totalSupply -= amount;
                    balances[owner] -= amount;
                    Redeem(amount);
                }
            
                function setParams(uint newBasisPoints, uint newMaxFee) public onlyOwner {
                    // Ensure transparency by hardcoding limit beyond which fees can never be added
                    require(newBasisPoints < 20);
                    require(newMaxFee < 50);
            
                    basisPointsRate = newBasisPoints;
                    maximumFee = newMaxFee.mul(10**decimals);
            
                    Params(basisPointsRate, maximumFee);
                }
            
                // Called when new token are issued
                event Issue(uint amount);
            
                // Called when tokens are redeemed
                event Redeem(uint amount);
            
                // Called when contract is deprecated
                event Deprecate(address newAddress);
            
                // Called if contract ever adds fees
                event Params(uint feeBasisPoints, uint maxFee);
            }

            File 3 of 3: YBSV1_1
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.9.0) (access/AccessControlDefaultAdminRules.sol)
            pragma solidity ^0.8.0;
            import "./AccessControlUpgradeable.sol";
            import "./IAccessControlDefaultAdminRulesUpgradeable.sol";
            import "../utils/math/SafeCastUpgradeable.sol";
            import "../interfaces/IERC5313Upgradeable.sol";
            import {Initializable} from "../proxy/utils/Initializable.sol";
            /**
             * @dev Extension of {AccessControl} that allows specifying special rules to manage
             * the `DEFAULT_ADMIN_ROLE` holder, which is a sensitive role with special permissions
             * over other roles that may potentially have privileged rights in the system.
             *
             * If a specific role doesn't have an admin role assigned, the holder of the
             * `DEFAULT_ADMIN_ROLE` will have the ability to grant it and revoke it.
             *
             * This contract implements the following risk mitigations on top of {AccessControl}:
             *
             * * Only one account holds the `DEFAULT_ADMIN_ROLE` since deployment until it's potentially renounced.
             * * Enforces a 2-step process to transfer the `DEFAULT_ADMIN_ROLE` to another account.
             * * Enforces a configurable delay between the two steps, with the ability to cancel before the transfer is accepted.
             * * The delay can be changed by scheduling, see {changeDefaultAdminDelay}.
             * * It is not possible to use another role to manage the `DEFAULT_ADMIN_ROLE`.
             *
             * Example usage:
             *
             * ```solidity
             * contract MyToken is AccessControlDefaultAdminRules {
             *   constructor() AccessControlDefaultAdminRules(
             *     3 days,
             *     msg.sender // Explicit initial `DEFAULT_ADMIN_ROLE` holder
             *    ) {}
             * }
             * ```
             *
             * _Available since v4.9._
             */
            abstract contract AccessControlDefaultAdminRulesUpgradeable is Initializable, IAccessControlDefaultAdminRulesUpgradeable, IERC5313Upgradeable, AccessControlUpgradeable {
                // pending admin pair read/written together frequently
                address private _pendingDefaultAdmin;
                uint48 private _pendingDefaultAdminSchedule; // 0 == unset
                uint48 private _currentDelay;
                address private _currentDefaultAdmin;
                // pending delay pair read/written together frequently
                uint48 private _pendingDelay;
                uint48 private _pendingDelaySchedule; // 0 == unset
                /**
                 * @dev Sets the initial values for {defaultAdminDelay} and {defaultAdmin} address.
                 */
                function __AccessControlDefaultAdminRules_init(uint48 initialDelay, address initialDefaultAdmin) internal onlyInitializing {
                    __AccessControlDefaultAdminRules_init_unchained(initialDelay, initialDefaultAdmin);
                }
                function __AccessControlDefaultAdminRules_init_unchained(uint48 initialDelay, address initialDefaultAdmin) internal onlyInitializing {
                    require(initialDefaultAdmin != address(0), "AccessControl: 0 default admin");
                    _currentDelay = initialDelay;
                    _grantRole(DEFAULT_ADMIN_ROLE, initialDefaultAdmin);
                }
                /**
                 * @dev See {IERC165-supportsInterface}.
                 */
                function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
                    return interfaceId == type(IAccessControlDefaultAdminRulesUpgradeable).interfaceId || super.supportsInterface(interfaceId);
                }
                /**
                 * @dev See {IERC5313-owner}.
                 */
                function owner() public view virtual returns (address) {
                    return defaultAdmin();
                }
                ///
                /// Override AccessControl role management
                ///
                /**
                 * @dev See {AccessControl-grantRole}. Reverts for `DEFAULT_ADMIN_ROLE`.
                 */
                function grantRole(bytes32 role, address account) public virtual override(AccessControlUpgradeable, IAccessControlUpgradeable) {
                    require(role != DEFAULT_ADMIN_ROLE, "AccessControl: can't directly grant default admin role");
                    super.grantRole(role, account);
                }
                /**
                 * @dev See {AccessControl-revokeRole}. Reverts for `DEFAULT_ADMIN_ROLE`.
                 */
                function revokeRole(bytes32 role, address account) public virtual override(AccessControlUpgradeable, IAccessControlUpgradeable) {
                    require(role != DEFAULT_ADMIN_ROLE, "AccessControl: can't directly revoke default admin role");
                    super.revokeRole(role, account);
                }
                /**
                 * @dev See {AccessControl-renounceRole}.
                 *
                 * For the `DEFAULT_ADMIN_ROLE`, it only allows renouncing in two steps by first calling
                 * {beginDefaultAdminTransfer} to the `address(0)`, so it's required that the {pendingDefaultAdmin} schedule
                 * has also passed when calling this function.
                 *
                 * After its execution, it will not be possible to call `onlyRole(DEFAULT_ADMIN_ROLE)` functions.
                 *
                 * NOTE: Renouncing `DEFAULT_ADMIN_ROLE` will leave the contract without a {defaultAdmin},
                 * thereby disabling any functionality that is only available for it, and the possibility of reassigning a
                 * non-administrated role.
                 */
                function renounceRole(bytes32 role, address account) public virtual override(AccessControlUpgradeable, IAccessControlUpgradeable) {
                    if (role == DEFAULT_ADMIN_ROLE && account == defaultAdmin()) {
                        (address newDefaultAdmin, uint48 schedule) = pendingDefaultAdmin();
                        require(
                            newDefaultAdmin == address(0) && _isScheduleSet(schedule) && _hasSchedulePassed(schedule),
                            "AccessControl: only can renounce in two delayed steps"
                        );
                        delete _pendingDefaultAdminSchedule;
                    }
                    super.renounceRole(role, account);
                }
                /**
                 * @dev See {AccessControl-_grantRole}.
                 *
                 * For `DEFAULT_ADMIN_ROLE`, it only allows granting if there isn't already a {defaultAdmin} or if the
                 * role has been previously renounced.
                 *
                 * NOTE: Exposing this function through another mechanism may make the `DEFAULT_ADMIN_ROLE`
                 * assignable again. Make sure to guarantee this is the expected behavior in your implementation.
                 */
                function _grantRole(bytes32 role, address account) internal virtual override {
                    if (role == DEFAULT_ADMIN_ROLE) {
                        require(defaultAdmin() == address(0), "AccessControl: default admin already granted");
                        _currentDefaultAdmin = account;
                    }
                    super._grantRole(role, account);
                }
                /**
                 * @dev See {AccessControl-_revokeRole}.
                 */
                function _revokeRole(bytes32 role, address account) internal virtual override {
                    if (role == DEFAULT_ADMIN_ROLE && account == defaultAdmin()) {
                        delete _currentDefaultAdmin;
                    }
                    super._revokeRole(role, account);
                }
                /**
                 * @dev See {AccessControl-_setRoleAdmin}. Reverts for `DEFAULT_ADMIN_ROLE`.
                 */
                function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual override {
                    require(role != DEFAULT_ADMIN_ROLE, "AccessControl: can't violate default admin rules");
                    super._setRoleAdmin(role, adminRole);
                }
                ///
                /// AccessControlDefaultAdminRules accessors
                ///
                /**
                 * @inheritdoc IAccessControlDefaultAdminRulesUpgradeable
                 */
                function defaultAdmin() public view virtual returns (address) {
                    return _currentDefaultAdmin;
                }
                /**
                 * @inheritdoc IAccessControlDefaultAdminRulesUpgradeable
                 */
                function pendingDefaultAdmin() public view virtual returns (address newAdmin, uint48 schedule) {
                    return (_pendingDefaultAdmin, _pendingDefaultAdminSchedule);
                }
                /**
                 * @inheritdoc IAccessControlDefaultAdminRulesUpgradeable
                 */
                function defaultAdminDelay() public view virtual returns (uint48) {
                    uint48 schedule = _pendingDelaySchedule;
                    return (_isScheduleSet(schedule) && _hasSchedulePassed(schedule)) ? _pendingDelay : _currentDelay;
                }
                /**
                 * @inheritdoc IAccessControlDefaultAdminRulesUpgradeable
                 */
                function pendingDefaultAdminDelay() public view virtual returns (uint48 newDelay, uint48 schedule) {
                    schedule = _pendingDelaySchedule;
                    return (_isScheduleSet(schedule) && !_hasSchedulePassed(schedule)) ? (_pendingDelay, schedule) : (0, 0);
                }
                /**
                 * @inheritdoc IAccessControlDefaultAdminRulesUpgradeable
                 */
                function defaultAdminDelayIncreaseWait() public view virtual returns (uint48) {
                    return 5 days;
                }
                ///
                /// AccessControlDefaultAdminRules public and internal setters for defaultAdmin/pendingDefaultAdmin
                ///
                /**
                 * @inheritdoc IAccessControlDefaultAdminRulesUpgradeable
                 */
                function beginDefaultAdminTransfer(address newAdmin) public virtual onlyRole(DEFAULT_ADMIN_ROLE) {
                    _beginDefaultAdminTransfer(newAdmin);
                }
                /**
                 * @dev See {beginDefaultAdminTransfer}.
                 *
                 * Internal function without access restriction.
                 */
                function _beginDefaultAdminTransfer(address newAdmin) internal virtual {
                    uint48 newSchedule = SafeCastUpgradeable.toUint48(block.timestamp) + defaultAdminDelay();
                    _setPendingDefaultAdmin(newAdmin, newSchedule);
                    emit DefaultAdminTransferScheduled(newAdmin, newSchedule);
                }
                /**
                 * @inheritdoc IAccessControlDefaultAdminRulesUpgradeable
                 */
                function cancelDefaultAdminTransfer() public virtual onlyRole(DEFAULT_ADMIN_ROLE) {
                    _cancelDefaultAdminTransfer();
                }
                /**
                 * @dev See {cancelDefaultAdminTransfer}.
                 *
                 * Internal function without access restriction.
                 */
                function _cancelDefaultAdminTransfer() internal virtual {
                    _setPendingDefaultAdmin(address(0), 0);
                }
                /**
                 * @inheritdoc IAccessControlDefaultAdminRulesUpgradeable
                 */
                function acceptDefaultAdminTransfer() public virtual {
                    (address newDefaultAdmin, ) = pendingDefaultAdmin();
                    require(_msgSender() == newDefaultAdmin, "AccessControl: pending admin must accept");
                    _acceptDefaultAdminTransfer();
                }
                /**
                 * @dev See {acceptDefaultAdminTransfer}.
                 *
                 * Internal function without access restriction.
                 */
                function _acceptDefaultAdminTransfer() internal virtual {
                    (address newAdmin, uint48 schedule) = pendingDefaultAdmin();
                    require(_isScheduleSet(schedule) && _hasSchedulePassed(schedule), "AccessControl: transfer delay not passed");
                    _revokeRole(DEFAULT_ADMIN_ROLE, defaultAdmin());
                    _grantRole(DEFAULT_ADMIN_ROLE, newAdmin);
                    delete _pendingDefaultAdmin;
                    delete _pendingDefaultAdminSchedule;
                }
                ///
                /// AccessControlDefaultAdminRules public and internal setters for defaultAdminDelay/pendingDefaultAdminDelay
                ///
                /**
                 * @inheritdoc IAccessControlDefaultAdminRulesUpgradeable
                 */
                function changeDefaultAdminDelay(uint48 newDelay) public virtual onlyRole(DEFAULT_ADMIN_ROLE) {
                    _changeDefaultAdminDelay(newDelay);
                }
                /**
                 * @dev See {changeDefaultAdminDelay}.
                 *
                 * Internal function without access restriction.
                 */
                function _changeDefaultAdminDelay(uint48 newDelay) internal virtual {
                    uint48 newSchedule = SafeCastUpgradeable.toUint48(block.timestamp) + _delayChangeWait(newDelay);
                    _setPendingDelay(newDelay, newSchedule);
                    emit DefaultAdminDelayChangeScheduled(newDelay, newSchedule);
                }
                /**
                 * @inheritdoc IAccessControlDefaultAdminRulesUpgradeable
                 */
                function rollbackDefaultAdminDelay() public virtual onlyRole(DEFAULT_ADMIN_ROLE) {
                    _rollbackDefaultAdminDelay();
                }
                /**
                 * @dev See {rollbackDefaultAdminDelay}.
                 *
                 * Internal function without access restriction.
                 */
                function _rollbackDefaultAdminDelay() internal virtual {
                    _setPendingDelay(0, 0);
                }
                /**
                 * @dev Returns the amount of seconds to wait after the `newDelay` will
                 * become the new {defaultAdminDelay}.
                 *
                 * The value returned guarantees that if the delay is reduced, it will go into effect
                 * after a wait that honors the previously set delay.
                 *
                 * See {defaultAdminDelayIncreaseWait}.
                 */
                function _delayChangeWait(uint48 newDelay) internal view virtual returns (uint48) {
                    uint48 currentDelay = defaultAdminDelay();
                    // When increasing the delay, we schedule the delay change to occur after a period of "new delay" has passed, up
                    // to a maximum given by defaultAdminDelayIncreaseWait, by default 5 days. For example, if increasing from 1 day
                    // to 3 days, the new delay will come into effect after 3 days. If increasing from 1 day to 10 days, the new
                    // delay will come into effect after 5 days. The 5 day wait period is intended to be able to fix an error like
                    // using milliseconds instead of seconds.
                    //
                    // When decreasing the delay, we wait the difference between "current delay" and "new delay". This guarantees
                    // that an admin transfer cannot be made faster than "current delay" at the time the delay change is scheduled.
                    // For example, if decreasing from 10 days to 3 days, the new delay will come into effect after 7 days.
                    return
                        newDelay > currentDelay
                            ? uint48(MathUpgradeable.min(newDelay, defaultAdminDelayIncreaseWait())) // no need to safecast, both inputs are uint48
                            : currentDelay - newDelay;
                }
                ///
                /// Private setters
                ///
                /**
                 * @dev Setter of the tuple for pending admin and its schedule.
                 *
                 * May emit a DefaultAdminTransferCanceled event.
                 */
                function _setPendingDefaultAdmin(address newAdmin, uint48 newSchedule) private {
                    (, uint48 oldSchedule) = pendingDefaultAdmin();
                    _pendingDefaultAdmin = newAdmin;
                    _pendingDefaultAdminSchedule = newSchedule;
                    // An `oldSchedule` from `pendingDefaultAdmin()` is only set if it hasn't been accepted.
                    if (_isScheduleSet(oldSchedule)) {
                        // Emit for implicit cancellations when another default admin was scheduled.
                        emit DefaultAdminTransferCanceled();
                    }
                }
                /**
                 * @dev Setter of the tuple for pending delay and its schedule.
                 *
                 * May emit a DefaultAdminDelayChangeCanceled event.
                 */
                function _setPendingDelay(uint48 newDelay, uint48 newSchedule) private {
                    uint48 oldSchedule = _pendingDelaySchedule;
                    if (_isScheduleSet(oldSchedule)) {
                        if (_hasSchedulePassed(oldSchedule)) {
                            // Materialize a virtual delay
                            _currentDelay = _pendingDelay;
                        } else {
                            // Emit for implicit cancellations when another delay was scheduled.
                            emit DefaultAdminDelayChangeCanceled();
                        }
                    }
                    _pendingDelay = newDelay;
                    _pendingDelaySchedule = newSchedule;
                }
                ///
                /// Private helpers
                ///
                /**
                 * @dev Defines if an `schedule` is considered set. For consistency purposes.
                 */
                function _isScheduleSet(uint48 schedule) private pure returns (bool) {
                    return schedule != 0;
                }
                /**
                 * @dev Defines if an `schedule` is considered passed. For consistency purposes.
                 */
                function _hasSchedulePassed(uint48 schedule) private view returns (bool) {
                    return schedule < block.timestamp;
                }
                /**
                 * @dev This empty reserved space is put in place to allow future versions to add new
                 * variables without shifting down storage in the inheritance chain.
                 * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
                 */
                uint256[48] private __gap;
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.9.0) (access/AccessControl.sol)
            pragma solidity ^0.8.0;
            import "./IAccessControlUpgradeable.sol";
            import "../utils/ContextUpgradeable.sol";
            import "../utils/StringsUpgradeable.sol";
            import "../utils/introspection/ERC165Upgradeable.sol";
            import {Initializable} from "../proxy/utils/Initializable.sol";
            /**
             * @dev Contract module that allows children to implement role-based access
             * control mechanisms. This is a lightweight version that doesn't allow enumerating role
             * members except through off-chain means by accessing the contract event logs. Some
             * applications may benefit from on-chain enumerability, for those cases see
             * {AccessControlEnumerable}.
             *
             * Roles are referred to by their `bytes32` identifier. These should be exposed
             * in the external API and be unique. The best way to achieve this is by
             * using `public constant` hash digests:
             *
             * ```solidity
             * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
             * ```
             *
             * Roles can be used to represent a set of permissions. To restrict access to a
             * function call, use {hasRole}:
             *
             * ```solidity
             * function foo() public {
             *     require(hasRole(MY_ROLE, msg.sender));
             *     ...
             * }
             * ```
             *
             * Roles can be granted and revoked dynamically via the {grantRole} and
             * {revokeRole} functions. Each role has an associated admin role, and only
             * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
             *
             * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
             * that only accounts with this role will be able to grant or revoke other
             * roles. More complex role relationships can be created by using
             * {_setRoleAdmin}.
             *
             * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
             * grant and revoke this role. Extra precautions should be taken to secure
             * accounts that have been granted it. We recommend using {AccessControlDefaultAdminRules}
             * to enforce additional security measures for this role.
             */
            abstract contract AccessControlUpgradeable is Initializable, ContextUpgradeable, IAccessControlUpgradeable, ERC165Upgradeable {
                struct RoleData {
                    mapping(address => bool) members;
                    bytes32 adminRole;
                }
                mapping(bytes32 => RoleData) private _roles;
                bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;
                /**
                 * @dev Modifier that checks that an account has a specific role. Reverts
                 * with a standardized message including the required role.
                 *
                 * The format of the revert reason is given by the following regular expression:
                 *
                 *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
                 *
                 * _Available since v4.1._
                 */
                modifier onlyRole(bytes32 role) {
                    _checkRole(role);
                    _;
                }
                function __AccessControl_init() internal onlyInitializing {
                }
                function __AccessControl_init_unchained() internal onlyInitializing {
                }
                /**
                 * @dev See {IERC165-supportsInterface}.
                 */
                function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
                    return interfaceId == type(IAccessControlUpgradeable).interfaceId || super.supportsInterface(interfaceId);
                }
                /**
                 * @dev Returns `true` if `account` has been granted `role`.
                 */
                function hasRole(bytes32 role, address account) public view virtual override returns (bool) {
                    return _roles[role].members[account];
                }
                /**
                 * @dev Revert with a standard message if `_msgSender()` is missing `role`.
                 * Overriding this function changes the behavior of the {onlyRole} modifier.
                 *
                 * Format of the revert message is described in {_checkRole}.
                 *
                 * _Available since v4.6._
                 */
                function _checkRole(bytes32 role) internal view virtual {
                    _checkRole(role, _msgSender());
                }
                /**
                 * @dev Revert with a standard message if `account` is missing `role`.
                 *
                 * The format of the revert reason is given by the following regular expression:
                 *
                 *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
                 */
                function _checkRole(bytes32 role, address account) internal view virtual {
                    if (!hasRole(role, account)) {
                        revert(
                            string(
                                abi.encodePacked(
                                    "AccessControl: account ",
                                    StringsUpgradeable.toHexString(account),
                                    " is missing role ",
                                    StringsUpgradeable.toHexString(uint256(role), 32)
                                )
                            )
                        );
                    }
                }
                /**
                 * @dev Returns the admin role that controls `role`. See {grantRole} and
                 * {revokeRole}.
                 *
                 * To change a role's admin, use {_setRoleAdmin}.
                 */
                function getRoleAdmin(bytes32 role) public view virtual override returns (bytes32) {
                    return _roles[role].adminRole;
                }
                /**
                 * @dev Grants `role` to `account`.
                 *
                 * If `account` had not been already granted `role`, emits a {RoleGranted}
                 * event.
                 *
                 * Requirements:
                 *
                 * - the caller must have ``role``'s admin role.
                 *
                 * May emit a {RoleGranted} event.
                 */
                function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
                    _grantRole(role, account);
                }
                /**
                 * @dev Revokes `role` from `account`.
                 *
                 * If `account` had been granted `role`, emits a {RoleRevoked} event.
                 *
                 * Requirements:
                 *
                 * - the caller must have ``role``'s admin role.
                 *
                 * May emit a {RoleRevoked} event.
                 */
                function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
                    _revokeRole(role, account);
                }
                /**
                 * @dev Revokes `role` from the calling account.
                 *
                 * Roles are often managed via {grantRole} and {revokeRole}: this function's
                 * purpose is to provide a mechanism for accounts to lose their privileges
                 * if they are compromised (such as when a trusted device is misplaced).
                 *
                 * If the calling account had been revoked `role`, emits a {RoleRevoked}
                 * event.
                 *
                 * Requirements:
                 *
                 * - the caller must be `account`.
                 *
                 * May emit a {RoleRevoked} event.
                 */
                function renounceRole(bytes32 role, address account) public virtual override {
                    require(account == _msgSender(), "AccessControl: can only renounce roles for self");
                    _revokeRole(role, account);
                }
                /**
                 * @dev Grants `role` to `account`.
                 *
                 * If `account` had not been already granted `role`, emits a {RoleGranted}
                 * event. Note that unlike {grantRole}, this function doesn't perform any
                 * checks on the calling account.
                 *
                 * May emit a {RoleGranted} event.
                 *
                 * [WARNING]
                 * ====
                 * This function should only be called from the constructor when setting
                 * up the initial roles for the system.
                 *
                 * Using this function in any other way is effectively circumventing the admin
                 * system imposed by {AccessControl}.
                 * ====
                 *
                 * NOTE: This function is deprecated in favor of {_grantRole}.
                 */
                function _setupRole(bytes32 role, address account) internal virtual {
                    _grantRole(role, account);
                }
                /**
                 * @dev Sets `adminRole` as ``role``'s admin role.
                 *
                 * Emits a {RoleAdminChanged} event.
                 */
                function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
                    bytes32 previousAdminRole = getRoleAdmin(role);
                    _roles[role].adminRole = adminRole;
                    emit RoleAdminChanged(role, previousAdminRole, adminRole);
                }
                /**
                 * @dev Grants `role` to `account`.
                 *
                 * Internal function without access restriction.
                 *
                 * May emit a {RoleGranted} event.
                 */
                function _grantRole(bytes32 role, address account) internal virtual {
                    if (!hasRole(role, account)) {
                        _roles[role].members[account] = true;
                        emit RoleGranted(role, account, _msgSender());
                    }
                }
                /**
                 * @dev Revokes `role` from `account`.
                 *
                 * Internal function without access restriction.
                 *
                 * May emit a {RoleRevoked} event.
                 */
                function _revokeRole(bytes32 role, address account) internal virtual {
                    if (hasRole(role, account)) {
                        _roles[role].members[account] = false;
                        emit RoleRevoked(role, account, _msgSender());
                    }
                }
                /**
                 * @dev This empty reserved space is put in place to allow future versions to add new
                 * variables without shifting down storage in the inheritance chain.
                 * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
                 */
                uint256[49] private __gap;
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.9.0) (access/IAccessControlDefaultAdminRules.sol)
            pragma solidity ^0.8.0;
            import "./IAccessControlUpgradeable.sol";
            /**
             * @dev External interface of AccessControlDefaultAdminRules declared to support ERC165 detection.
             *
             * _Available since v4.9._
             */
            interface IAccessControlDefaultAdminRulesUpgradeable is IAccessControlUpgradeable {
                /**
                 * @dev Emitted when a {defaultAdmin} transfer is started, setting `newAdmin` as the next
                 * address to become the {defaultAdmin} by calling {acceptDefaultAdminTransfer} only after `acceptSchedule`
                 * passes.
                 */
                event DefaultAdminTransferScheduled(address indexed newAdmin, uint48 acceptSchedule);
                /**
                 * @dev Emitted when a {pendingDefaultAdmin} is reset if it was never accepted, regardless of its schedule.
                 */
                event DefaultAdminTransferCanceled();
                /**
                 * @dev Emitted when a {defaultAdminDelay} change is started, setting `newDelay` as the next
                 * delay to be applied between default admin transfer after `effectSchedule` has passed.
                 */
                event DefaultAdminDelayChangeScheduled(uint48 newDelay, uint48 effectSchedule);
                /**
                 * @dev Emitted when a {pendingDefaultAdminDelay} is reset if its schedule didn't pass.
                 */
                event DefaultAdminDelayChangeCanceled();
                /**
                 * @dev Returns the address of the current `DEFAULT_ADMIN_ROLE` holder.
                 */
                function defaultAdmin() external view returns (address);
                /**
                 * @dev Returns a tuple of a `newAdmin` and an accept schedule.
                 *
                 * After the `schedule` passes, the `newAdmin` will be able to accept the {defaultAdmin} role
                 * by calling {acceptDefaultAdminTransfer}, completing the role transfer.
                 *
                 * A zero value only in `acceptSchedule` indicates no pending admin transfer.
                 *
                 * NOTE: A zero address `newAdmin` means that {defaultAdmin} is being renounced.
                 */
                function pendingDefaultAdmin() external view returns (address newAdmin, uint48 acceptSchedule);
                /**
                 * @dev Returns the delay required to schedule the acceptance of a {defaultAdmin} transfer started.
                 *
                 * This delay will be added to the current timestamp when calling {beginDefaultAdminTransfer} to set
                 * the acceptance schedule.
                 *
                 * NOTE: If a delay change has been scheduled, it will take effect as soon as the schedule passes, making this
                 * function returns the new delay. See {changeDefaultAdminDelay}.
                 */
                function defaultAdminDelay() external view returns (uint48);
                /**
                 * @dev Returns a tuple of `newDelay` and an effect schedule.
                 *
                 * After the `schedule` passes, the `newDelay` will get into effect immediately for every
                 * new {defaultAdmin} transfer started with {beginDefaultAdminTransfer}.
                 *
                 * A zero value only in `effectSchedule` indicates no pending delay change.
                 *
                 * NOTE: A zero value only for `newDelay` means that the next {defaultAdminDelay}
                 * will be zero after the effect schedule.
                 */
                function pendingDefaultAdminDelay() external view returns (uint48 newDelay, uint48 effectSchedule);
                /**
                 * @dev Starts a {defaultAdmin} transfer by setting a {pendingDefaultAdmin} scheduled for acceptance
                 * after the current timestamp plus a {defaultAdminDelay}.
                 *
                 * Requirements:
                 *
                 * - Only can be called by the current {defaultAdmin}.
                 *
                 * Emits a DefaultAdminRoleChangeStarted event.
                 */
                function beginDefaultAdminTransfer(address newAdmin) external;
                /**
                 * @dev Cancels a {defaultAdmin} transfer previously started with {beginDefaultAdminTransfer}.
                 *
                 * A {pendingDefaultAdmin} not yet accepted can also be cancelled with this function.
                 *
                 * Requirements:
                 *
                 * - Only can be called by the current {defaultAdmin}.
                 *
                 * May emit a DefaultAdminTransferCanceled event.
                 */
                function cancelDefaultAdminTransfer() external;
                /**
                 * @dev Completes a {defaultAdmin} transfer previously started with {beginDefaultAdminTransfer}.
                 *
                 * After calling the function:
                 *
                 * - `DEFAULT_ADMIN_ROLE` should be granted to the caller.
                 * - `DEFAULT_ADMIN_ROLE` should be revoked from the previous holder.
                 * - {pendingDefaultAdmin} should be reset to zero values.
                 *
                 * Requirements:
                 *
                 * - Only can be called by the {pendingDefaultAdmin}'s `newAdmin`.
                 * - The {pendingDefaultAdmin}'s `acceptSchedule` should've passed.
                 */
                function acceptDefaultAdminTransfer() external;
                /**
                 * @dev Initiates a {defaultAdminDelay} update by setting a {pendingDefaultAdminDelay} scheduled for getting
                 * into effect after the current timestamp plus a {defaultAdminDelay}.
                 *
                 * This function guarantees that any call to {beginDefaultAdminTransfer} done between the timestamp this
                 * method is called and the {pendingDefaultAdminDelay} effect schedule will use the current {defaultAdminDelay}
                 * set before calling.
                 *
                 * The {pendingDefaultAdminDelay}'s effect schedule is defined in a way that waiting until the schedule and then
                 * calling {beginDefaultAdminTransfer} with the new delay will take at least the same as another {defaultAdmin}
                 * complete transfer (including acceptance).
                 *
                 * The schedule is designed for two scenarios:
                 *
                 * - When the delay is changed for a larger one the schedule is `block.timestamp + newDelay` capped by
                 * {defaultAdminDelayIncreaseWait}.
                 * - When the delay is changed for a shorter one, the schedule is `block.timestamp + (current delay - new delay)`.
                 *
                 * A {pendingDefaultAdminDelay} that never got into effect will be canceled in favor of a new scheduled change.
                 *
                 * Requirements:
                 *
                 * - Only can be called by the current {defaultAdmin}.
                 *
                 * Emits a DefaultAdminDelayChangeScheduled event and may emit a DefaultAdminDelayChangeCanceled event.
                 */
                function changeDefaultAdminDelay(uint48 newDelay) external;
                /**
                 * @dev Cancels a scheduled {defaultAdminDelay} change.
                 *
                 * Requirements:
                 *
                 * - Only can be called by the current {defaultAdmin}.
                 *
                 * May emit a DefaultAdminDelayChangeCanceled event.
                 */
                function rollbackDefaultAdminDelay() external;
                /**
                 * @dev Maximum time in seconds for an increase to {defaultAdminDelay} (that is scheduled using {changeDefaultAdminDelay})
                 * to take effect. Default to 5 days.
                 *
                 * When the {defaultAdminDelay} is scheduled to be increased, it goes into effect after the new delay has passed with
                 * the purpose of giving enough time for reverting any accidental change (i.e. using milliseconds instead of seconds)
                 * that may lock the contract. However, to avoid excessive schedules, the wait is capped by this function and it can
                 * be overrode for a custom {defaultAdminDelay} increase scheduling.
                 *
                 * IMPORTANT: Make sure to add a reasonable amount of time while overriding this value, otherwise,
                 * there's a risk of setting a high new delay that goes into effect almost immediately without the
                 * possibility of human intervention in the case of an input error (eg. set milliseconds instead of seconds).
                 */
                function defaultAdminDelayIncreaseWait() external view returns (uint48);
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts v4.4.1 (access/IAccessControl.sol)
            pragma solidity ^0.8.0;
            /**
             * @dev External interface of AccessControl declared to support ERC165 detection.
             */
            interface IAccessControlUpgradeable {
                /**
                 * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
                 *
                 * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
                 * {RoleAdminChanged} not being emitted signaling this.
                 *
                 * _Available since v3.1._
                 */
                event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);
                /**
                 * @dev Emitted when `account` is granted `role`.
                 *
                 * `sender` is the account that originated the contract call, an admin role
                 * bearer except when using {AccessControl-_setupRole}.
                 */
                event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);
                /**
                 * @dev Emitted when `account` is revoked `role`.
                 *
                 * `sender` is the account that originated the contract call:
                 *   - if using `revokeRole`, it is the admin role bearer
                 *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
                 */
                event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);
                /**
                 * @dev Returns `true` if `account` has been granted `role`.
                 */
                function hasRole(bytes32 role, address account) external view returns (bool);
                /**
                 * @dev Returns the admin role that controls `role`. See {grantRole} and
                 * {revokeRole}.
                 *
                 * To change a role's admin, use {AccessControl-_setRoleAdmin}.
                 */
                function getRoleAdmin(bytes32 role) external view returns (bytes32);
                /**
                 * @dev Grants `role` to `account`.
                 *
                 * If `account` had not been already granted `role`, emits a {RoleGranted}
                 * event.
                 *
                 * Requirements:
                 *
                 * - the caller must have ``role``'s admin role.
                 */
                function grantRole(bytes32 role, address account) external;
                /**
                 * @dev Revokes `role` from `account`.
                 *
                 * If `account` had been granted `role`, emits a {RoleRevoked} event.
                 *
                 * Requirements:
                 *
                 * - the caller must have ``role``'s admin role.
                 */
                function revokeRole(bytes32 role, address account) external;
                /**
                 * @dev Revokes `role` from the calling account.
                 *
                 * Roles are often managed via {grantRole} and {revokeRole}: this function's
                 * purpose is to provide a mechanism for accounts to lose their privileges
                 * if they are compromised (such as when a trusted device is misplaced).
                 *
                 * If the calling account had been granted `role`, emits a {RoleRevoked}
                 * event.
                 *
                 * Requirements:
                 *
                 * - the caller must be `account`.
                 */
                function renounceRole(bytes32 role, address account) external;
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.5.0) (interfaces/draft-IERC1822.sol)
            pragma solidity ^0.8.0;
            /**
             * @dev ERC1822: Universal Upgradeable Proxy Standard (UUPS) documents a method for upgradeability through a simplified
             * proxy whose upgrades are fully controlled by the current implementation.
             */
            interface IERC1822ProxiableUpgradeable {
                /**
                 * @dev Returns the storage slot that the proxiable contract assumes is being used to store the implementation
                 * address.
                 *
                 * IMPORTANT: A proxy pointing at a proxiable contract should not be considered proxiable itself, because this risks
                 * bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this
                 * function revert if invoked through a proxy.
                 */
                function proxiableUUID() external view returns (bytes32);
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.9.0) (interfaces/IERC1967.sol)
            pragma solidity ^0.8.0;
            /**
             * @dev ERC-1967: Proxy Storage Slots. This interface contains the events defined in the ERC.
             *
             * _Available since v4.8.3._
             */
            interface IERC1967Upgradeable {
                /**
                 * @dev Emitted when the implementation is upgraded.
                 */
                event Upgraded(address indexed implementation);
                /**
                 * @dev Emitted when the admin account has changed.
                 */
                event AdminChanged(address previousAdmin, address newAdmin);
                /**
                 * @dev Emitted when the beacon is changed.
                 */
                event BeaconUpgraded(address indexed beacon);
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.9.0) (interfaces/IERC5313.sol)
            pragma solidity ^0.8.0;
            /**
             * @dev Interface for the Light Contract Ownership Standard.
             *
             * A standardized minimal interface required to identify an account that controls a contract
             *
             * _Available since v4.9._
             */
            interface IERC5313Upgradeable {
                /**
                 * @dev Gets the address of the owner.
                 */
                function owner() external view returns (address);
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts v4.4.1 (proxy/beacon/IBeacon.sol)
            pragma solidity ^0.8.0;
            /**
             * @dev This is the interface that {BeaconProxy} expects of its beacon.
             */
            interface IBeaconUpgradeable {
                /**
                 * @dev Must return an address that can be used as a delegate call target.
                 *
                 * {BeaconProxy} will check that this address is a contract.
                 */
                function implementation() external view returns (address);
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.9.0) (proxy/ERC1967/ERC1967Upgrade.sol)
            pragma solidity ^0.8.2;
            import "../beacon/IBeaconUpgradeable.sol";
            import "../../interfaces/IERC1967Upgradeable.sol";
            import "../../interfaces/draft-IERC1822Upgradeable.sol";
            import "../../utils/AddressUpgradeable.sol";
            import "../../utils/StorageSlotUpgradeable.sol";
            import {Initializable} from "../utils/Initializable.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._
             */
            abstract contract ERC1967UpgradeUpgradeable is Initializable, IERC1967Upgradeable {
                // 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;
                function __ERC1967Upgrade_init() internal onlyInitializing {
                }
                function __ERC1967Upgrade_init_unchained() internal onlyInitializing {
                }
                /**
                 * @dev Returns the current implementation address.
                 */
                function _getImplementation() internal view returns (address) {
                    return StorageSlotUpgradeable.getAddressSlot(_IMPLEMENTATION_SLOT).value;
                }
                /**
                 * @dev Stores a new address in the EIP1967 implementation slot.
                 */
                function _setImplementation(address newImplementation) private {
                    require(AddressUpgradeable.isContract(newImplementation), "ERC1967: new implementation is not a contract");
                    StorageSlotUpgradeable.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) {
                        AddressUpgradeable.functionDelegateCall(newImplementation, data);
                    }
                }
                /**
                 * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
                 *
                 * Emits an {Upgraded} event.
                 */
                function _upgradeToAndCallUUPS(address newImplementation, bytes memory data, bool forceCall) internal {
                    // Upgrades from old implementations will perform a rollback test. This test requires the new
                    // implementation to upgrade back to the old, non-ERC1822 compliant, implementation. Removing
                    // this special case will break upgrade paths from old UUPS implementation to new ones.
                    if (StorageSlotUpgradeable.getBooleanSlot(_ROLLBACK_SLOT).value) {
                        _setImplementation(newImplementation);
                    } else {
                        try IERC1822ProxiableUpgradeable(newImplementation).proxiableUUID() returns (bytes32 slot) {
                            require(slot == _IMPLEMENTATION_SLOT, "ERC1967Upgrade: unsupported proxiableUUID");
                        } catch {
                            revert("ERC1967Upgrade: new implementation is not UUPS");
                        }
                        _upgradeToAndCall(newImplementation, data, forceCall);
                    }
                }
                /**
                 * @dev Storage slot with the admin of the contract.
                 * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
                 * validated in the constructor.
                 */
                bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
                /**
                 * @dev Returns the current admin.
                 */
                function _getAdmin() internal view returns (address) {
                    return StorageSlotUpgradeable.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");
                    StorageSlotUpgradeable.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
                }
                /**
                 * @dev Changes the admin of the proxy.
                 *
                 * Emits an {AdminChanged} event.
                 */
                function _changeAdmin(address newAdmin) internal {
                    emit AdminChanged(_getAdmin(), newAdmin);
                    _setAdmin(newAdmin);
                }
                /**
                 * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
                 * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
                 */
                bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
                /**
                 * @dev Returns the current beacon.
                 */
                function _getBeacon() internal view returns (address) {
                    return StorageSlotUpgradeable.getAddressSlot(_BEACON_SLOT).value;
                }
                /**
                 * @dev Stores a new beacon in the EIP1967 beacon slot.
                 */
                function _setBeacon(address newBeacon) private {
                    require(AddressUpgradeable.isContract(newBeacon), "ERC1967: new beacon is not a contract");
                    require(
                        AddressUpgradeable.isContract(IBeaconUpgradeable(newBeacon).implementation()),
                        "ERC1967: beacon implementation is not a contract"
                    );
                    StorageSlotUpgradeable.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) {
                        AddressUpgradeable.functionDelegateCall(IBeaconUpgradeable(newBeacon).implementation(), data);
                    }
                }
                /**
                 * @dev This empty reserved space is put in place to allow future versions to add new
                 * variables without shifting down storage in the inheritance chain.
                 * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
                 */
                uint256[50] private __gap;
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.9.0) (proxy/utils/Initializable.sol)
            pragma solidity ^0.8.2;
            import "../../utils/AddressUpgradeable.sol";
            /**
             * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
             * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an
             * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
             * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
             *
             * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be
             * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in
             * case an upgrade adds a module that needs to be initialized.
             *
             * For example:
             *
             * [.hljs-theme-light.nopadding]
             * ```solidity
             * contract MyToken is ERC20Upgradeable {
             *     function initialize() initializer public {
             *         __ERC20_init("MyToken", "MTK");
             *     }
             * }
             *
             * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {
             *     function initializeV2() reinitializer(2) public {
             *         __ERC20Permit_init("MyToken");
             *     }
             * }
             * ```
             *
             * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
             * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
             *
             * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
             * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
             *
             * [CAUTION]
             * ====
             * Avoid leaving a contract uninitialized.
             *
             * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
             * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke
             * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:
             *
             * [.hljs-theme-light.nopadding]
             * ```
             * /// @custom:oz-upgrades-unsafe-allow constructor
             * constructor() {
             *     _disableInitializers();
             * }
             * ```
             * ====
             */
            abstract contract Initializable {
                /**
                 * @dev Indicates that the contract has been initialized.
                 * @custom:oz-retyped-from bool
                 */
                uint8 private _initialized;
                /**
                 * @dev Indicates that the contract is in the process of being initialized.
                 */
                bool private _initializing;
                /**
                 * @dev Triggered when the contract has been initialized or reinitialized.
                 */
                event Initialized(uint8 version);
                /**
                 * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
                 * `onlyInitializing` functions can be used to initialize parent contracts.
                 *
                 * Similar to `reinitializer(1)`, except that functions marked with `initializer` can be nested in the context of a
                 * constructor.
                 *
                 * Emits an {Initialized} event.
                 */
                modifier initializer() {
                    bool isTopLevelCall = !_initializing;
                    require(
                        (isTopLevelCall && _initialized < 1) || (!AddressUpgradeable.isContract(address(this)) && _initialized == 1),
                        "Initializable: contract is already initialized"
                    );
                    _initialized = 1;
                    if (isTopLevelCall) {
                        _initializing = true;
                    }
                    _;
                    if (isTopLevelCall) {
                        _initializing = false;
                        emit Initialized(1);
                    }
                }
                /**
                 * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
                 * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
                 * used to initialize parent contracts.
                 *
                 * A reinitializer may be used after the original initialization step. This is essential to configure modules that
                 * are added through upgrades and that require initialization.
                 *
                 * When `version` is 1, this modifier is similar to `initializer`, except that functions marked with `reinitializer`
                 * cannot be nested. If one is invoked in the context of another, execution will revert.
                 *
                 * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
                 * a contract, executing them in the right order is up to the developer or operator.
                 *
                 * WARNING: setting the version to 255 will prevent any future reinitialization.
                 *
                 * Emits an {Initialized} event.
                 */
                modifier reinitializer(uint8 version) {
                    require(!_initializing && _initialized < version, "Initializable: contract is already initialized");
                    _initialized = version;
                    _initializing = true;
                    _;
                    _initializing = false;
                    emit Initialized(version);
                }
                /**
                 * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
                 * {initializer} and {reinitializer} modifiers, directly or indirectly.
                 */
                modifier onlyInitializing() {
                    require(_initializing, "Initializable: contract is not initializing");
                    _;
                }
                /**
                 * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.
                 * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized
                 * to any version. It is recommended to use this to lock implementation contracts that are designed to be called
                 * through proxies.
                 *
                 * Emits an {Initialized} event the first time it is successfully executed.
                 */
                function _disableInitializers() internal virtual {
                    require(!_initializing, "Initializable: contract is initializing");
                    if (_initialized != type(uint8).max) {
                        _initialized = type(uint8).max;
                        emit Initialized(type(uint8).max);
                    }
                }
                /**
                 * @dev Returns the highest version that has been initialized. See {reinitializer}.
                 */
                function _getInitializedVersion() internal view returns (uint8) {
                    return _initialized;
                }
                /**
                 * @dev Returns `true` if the contract is currently initializing. See {onlyInitializing}.
                 */
                function _isInitializing() internal view returns (bool) {
                    return _initializing;
                }
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.9.0) (proxy/utils/UUPSUpgradeable.sol)
            pragma solidity ^0.8.0;
            import "../../interfaces/draft-IERC1822Upgradeable.sol";
            import "../ERC1967/ERC1967UpgradeUpgradeable.sol";
            import {Initializable} from "./Initializable.sol";
            /**
             * @dev An upgradeability mechanism designed for UUPS proxies. The functions included here can perform an upgrade of an
             * {ERC1967Proxy}, when this contract is set as the implementation behind such a proxy.
             *
             * A security mechanism ensures that an upgrade does not turn off upgradeability accidentally, although this risk is
             * reinstated if the upgrade retains upgradeability but removes the security mechanism, e.g. by replacing
             * `UUPSUpgradeable` with a custom implementation of upgrades.
             *
             * The {_authorizeUpgrade} function must be overridden to include access restriction to the upgrade mechanism.
             *
             * _Available since v4.1._
             */
            abstract contract UUPSUpgradeable is Initializable, IERC1822ProxiableUpgradeable, ERC1967UpgradeUpgradeable {
                /// @custom:oz-upgrades-unsafe-allow state-variable-immutable state-variable-assignment
                address private immutable __self = address(this);
                /**
                 * @dev Check that the execution is being performed through a delegatecall call and that the execution context is
                 * a proxy contract with an implementation (as defined in ERC1967) pointing to self. This should only be the case
                 * for UUPS and transparent proxies that are using the current contract as their implementation. Execution of a
                 * function through ERC1167 minimal proxies (clones) would not normally pass this test, but is not guaranteed to
                 * fail.
                 */
                modifier onlyProxy() {
                    require(address(this) != __self, "Function must be called through delegatecall");
                    require(_getImplementation() == __self, "Function must be called through active proxy");
                    _;
                }
                /**
                 * @dev Check that the execution is not being performed through a delegate call. This allows a function to be
                 * callable on the implementing contract but not through proxies.
                 */
                modifier notDelegated() {
                    require(address(this) == __self, "UUPSUpgradeable: must not be called through delegatecall");
                    _;
                }
                function __UUPSUpgradeable_init() internal onlyInitializing {
                }
                function __UUPSUpgradeable_init_unchained() internal onlyInitializing {
                }
                /**
                 * @dev Implementation of the ERC1822 {proxiableUUID} function. This returns the storage slot used by the
                 * implementation. It is used to validate the implementation's compatibility when performing an upgrade.
                 *
                 * IMPORTANT: A proxy pointing at a proxiable contract should not be considered proxiable itself, because this risks
                 * bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this
                 * function revert if invoked through a proxy. This is guaranteed by the `notDelegated` modifier.
                 */
                function proxiableUUID() external view virtual override notDelegated returns (bytes32) {
                    return _IMPLEMENTATION_SLOT;
                }
                /**
                 * @dev Upgrade the implementation of the proxy to `newImplementation`.
                 *
                 * Calls {_authorizeUpgrade}.
                 *
                 * Emits an {Upgraded} event.
                 *
                 * @custom:oz-upgrades-unsafe-allow-reachable delegatecall
                 */
                function upgradeTo(address newImplementation) public virtual onlyProxy {
                    _authorizeUpgrade(newImplementation);
                    _upgradeToAndCallUUPS(newImplementation, new bytes(0), false);
                }
                /**
                 * @dev Upgrade the implementation of the proxy to `newImplementation`, and subsequently execute the function call
                 * encoded in `data`.
                 *
                 * Calls {_authorizeUpgrade}.
                 *
                 * Emits an {Upgraded} event.
                 *
                 * @custom:oz-upgrades-unsafe-allow-reachable delegatecall
                 */
                function upgradeToAndCall(address newImplementation, bytes memory data) public payable virtual onlyProxy {
                    _authorizeUpgrade(newImplementation);
                    _upgradeToAndCallUUPS(newImplementation, data, true);
                }
                /**
                 * @dev Function that should revert when `msg.sender` is not authorized to upgrade the contract. Called by
                 * {upgradeTo} and {upgradeToAndCall}.
                 *
                 * Normally, this function will use an xref:access.adoc[access control] modifier such as {Ownable-onlyOwner}.
                 *
                 * ```solidity
                 * function _authorizeUpgrade(address) internal override onlyOwner {}
                 * ```
                 */
                function _authorizeUpgrade(address newImplementation) internal virtual;
                /**
                 * @dev This empty reserved space is put in place to allow future versions to add new
                 * variables without shifting down storage in the inheritance chain.
                 * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
                 */
                uint256[50] private __gap;
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.7.0) (security/Pausable.sol)
            pragma solidity ^0.8.0;
            import "../utils/ContextUpgradeable.sol";
            import {Initializable} from "../proxy/utils/Initializable.sol";
            /**
             * @dev Contract module which allows children to implement an emergency stop
             * mechanism that can be triggered by an authorized account.
             *
             * This module is used through inheritance. It will make available the
             * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
             * the functions of your contract. Note that they will not be pausable by
             * simply including this module, only once the modifiers are put in place.
             */
            abstract contract PausableUpgradeable is Initializable, ContextUpgradeable {
                /**
                 * @dev Emitted when the pause is triggered by `account`.
                 */
                event Paused(address account);
                /**
                 * @dev Emitted when the pause is lifted by `account`.
                 */
                event Unpaused(address account);
                bool private _paused;
                /**
                 * @dev Initializes the contract in unpaused state.
                 */
                function __Pausable_init() internal onlyInitializing {
                    __Pausable_init_unchained();
                }
                function __Pausable_init_unchained() internal onlyInitializing {
                    _paused = false;
                }
                /**
                 * @dev Modifier to make a function callable only when the contract is not paused.
                 *
                 * Requirements:
                 *
                 * - The contract must not be paused.
                 */
                modifier whenNotPaused() {
                    _requireNotPaused();
                    _;
                }
                /**
                 * @dev Modifier to make a function callable only when the contract is paused.
                 *
                 * Requirements:
                 *
                 * - The contract must be paused.
                 */
                modifier whenPaused() {
                    _requirePaused();
                    _;
                }
                /**
                 * @dev Returns true if the contract is paused, and false otherwise.
                 */
                function paused() public view virtual returns (bool) {
                    return _paused;
                }
                /**
                 * @dev Throws if the contract is paused.
                 */
                function _requireNotPaused() internal view virtual {
                    require(!paused(), "Pausable: paused");
                }
                /**
                 * @dev Throws if the contract is not paused.
                 */
                function _requirePaused() internal view virtual {
                    require(paused(), "Pausable: not paused");
                }
                /**
                 * @dev Triggers stopped state.
                 *
                 * Requirements:
                 *
                 * - The contract must not be paused.
                 */
                function _pause() internal virtual whenNotPaused {
                    _paused = true;
                    emit Paused(_msgSender());
                }
                /**
                 * @dev Returns to normal state.
                 *
                 * Requirements:
                 *
                 * - The contract must be paused.
                 */
                function _unpause() internal virtual whenPaused {
                    _paused = false;
                    emit Unpaused(_msgSender());
                }
                /**
                 * @dev This empty reserved space is put in place to allow future versions to add new
                 * variables without shifting down storage in the inheritance chain.
                 * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
                 */
                uint256[49] private __gap;
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)
            pragma solidity ^0.8.0;
            import "../IERC20Upgradeable.sol";
            /**
             * @dev Interface for the optional metadata functions from the ERC20 standard.
             *
             * _Available since v4.1._
             */
            interface IERC20MetadataUpgradeable is IERC20Upgradeable {
                /**
                 * @dev Returns the name of the token.
                 */
                function name() external view returns (string memory);
                /**
                 * @dev Returns the symbol of the token.
                 */
                function symbol() external view returns (string memory);
                /**
                 * @dev Returns the decimals places of the token.
                 */
                function decimals() external view returns (uint8);
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)
            pragma solidity ^0.8.0;
            /**
             * @dev Interface of the ERC20 standard as defined in the EIP.
             */
            interface IERC20Upgradeable {
                /**
                 * @dev Emitted when `value` tokens are moved from one account (`from`) to
                 * another (`to`).
                 *
                 * Note that `value` may be zero.
                 */
                event Transfer(address indexed from, address indexed to, uint256 value);
                /**
                 * @dev Emitted when the allowance of a `spender` for an `owner` is set by
                 * a call to {approve}. `value` is the new allowance.
                 */
                event Approval(address indexed owner, address indexed spender, uint256 value);
                /**
                 * @dev Returns the amount of tokens in existence.
                 */
                function totalSupply() external view returns (uint256);
                /**
                 * @dev Returns the amount of tokens owned by `account`.
                 */
                function balanceOf(address account) external view returns (uint256);
                /**
                 * @dev Moves `amount` tokens from the caller's account to `to`.
                 *
                 * Returns a boolean value indicating whether the operation succeeded.
                 *
                 * Emits a {Transfer} event.
                 */
                function transfer(address to, uint256 amount) external returns (bool);
                /**
                 * @dev Returns the remaining number of tokens that `spender` will be
                 * allowed to spend on behalf of `owner` through {transferFrom}. This is
                 * zero by default.
                 *
                 * This value changes when {approve} or {transferFrom} are called.
                 */
                function allowance(address owner, address spender) external view returns (uint256);
                /**
                 * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
                 *
                 * Returns a boolean value indicating whether the operation succeeded.
                 *
                 * IMPORTANT: Beware that changing an allowance with this method brings the risk
                 * that someone may use both the old and the new allowance by unfortunate
                 * transaction ordering. One possible solution to mitigate this race
                 * condition is to first reduce the spender's allowance to 0 and set the
                 * desired value afterwards:
                 * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
                 *
                 * Emits an {Approval} event.
                 */
                function approve(address spender, uint256 amount) external returns (bool);
                /**
                 * @dev Moves `amount` tokens from `from` to `to` using the
                 * allowance mechanism. `amount` is then deducted from the caller's
                 * allowance.
                 *
                 * Returns a boolean value indicating whether the operation succeeded.
                 *
                 * Emits a {Transfer} event.
                 */
                function transferFrom(address from, address to, uint256 amount) external returns (bool);
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.9.0) (utils/Address.sol)
            pragma solidity ^0.8.1;
            /**
             * @dev Collection of functions related to the address type
             */
            library AddressUpgradeable {
                /**
                 * @dev Returns true if `account` is a contract.
                 *
                 * [IMPORTANT]
                 * ====
                 * It is unsafe to assume that an address for which this function returns
                 * false is an externally-owned account (EOA) and not a contract.
                 *
                 * Among others, `isContract` will return false for the following
                 * types of addresses:
                 *
                 *  - an externally-owned account
                 *  - a contract in construction
                 *  - an address where a contract will be created
                 *  - an address where a contract lived, but was destroyed
                 *
                 * Furthermore, `isContract` will also return true if the target contract within
                 * the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
                 * which only has an effect at the end of a transaction.
                 * ====
                 *
                 * [IMPORTANT]
                 * ====
                 * You shouldn't rely on `isContract` to protect against flash loan attacks!
                 *
                 * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
                 * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
                 * constructor.
                 * ====
                 */
                function isContract(address account) internal view returns (bool) {
                    // This method relies on extcodesize/address.code.length, which returns 0
                    // for contracts in construction, since the code is only stored at the end
                    // of the constructor execution.
                    return account.code.length > 0;
                }
                /**
                 * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
                 * `recipient`, forwarding all available gas and reverting on errors.
                 *
                 * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
                 * of certain opcodes, possibly making contracts go over the 2300 gas limit
                 * imposed by `transfer`, making them unable to receive funds via
                 * `transfer`. {sendValue} removes this limitation.
                 *
                 * https://consensys.net/diligence/blog/2019/09/stop-using-soliditys-transfer-now/[Learn more].
                 *
                 * IMPORTANT: because control is transferred to `recipient`, care must be
                 * taken to not create reentrancy vulnerabilities. Consider using
                 * {ReentrancyGuard} or the
                 * https://solidity.readthedocs.io/en/v0.8.0/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
                 */
                function sendValue(address payable recipient, uint256 amount) internal {
                    require(address(this).balance >= amount, "Address: insufficient balance");
                    (bool success, ) = recipient.call{value: amount}("");
                    require(success, "Address: unable to send value, recipient may have reverted");
                }
                /**
                 * @dev Performs a Solidity function call using a low level `call`. A
                 * plain `call` is an unsafe replacement for a function call: use this
                 * function instead.
                 *
                 * If `target` reverts with a revert reason, it is bubbled up by this
                 * function (like regular Solidity function calls).
                 *
                 * Returns the raw returned data. To convert to the expected return value,
                 * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
                 *
                 * Requirements:
                 *
                 * - `target` must be a contract.
                 * - calling `target` with `data` must not revert.
                 *
                 * _Available since v3.1._
                 */
                function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                    return functionCallWithValue(target, data, 0, "Address: low-level call failed");
                }
                /**
                 * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
                 * `errorMessage` as a fallback revert reason when `target` reverts.
                 *
                 * _Available since v3.1._
                 */
                function functionCall(
                    address target,
                    bytes memory data,
                    string memory errorMessage
                ) internal returns (bytes memory) {
                    return functionCallWithValue(target, data, 0, errorMessage);
                }
                /**
                 * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                 * but also transferring `value` wei to `target`.
                 *
                 * Requirements:
                 *
                 * - the calling contract must have an ETH balance of at least `value`.
                 * - the called Solidity function must be `payable`.
                 *
                 * _Available since v3.1._
                 */
                function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
                    return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
                }
                /**
                 * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
                 * with `errorMessage` as a fallback revert reason when `target` reverts.
                 *
                 * _Available since v3.1._
                 */
                function functionCallWithValue(
                    address target,
                    bytes memory data,
                    uint256 value,
                    string memory errorMessage
                ) internal returns (bytes memory) {
                    require(address(this).balance >= value, "Address: insufficient balance for call");
                    (bool success, bytes memory returndata) = target.call{value: value}(data);
                    return verifyCallResultFromTarget(target, success, returndata, errorMessage);
                }
                /**
                 * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                 * but performing a static call.
                 *
                 * _Available since v3.3._
                 */
                function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                    return functionStaticCall(target, data, "Address: low-level static call failed");
                }
                /**
                 * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                 * but performing a static call.
                 *
                 * _Available since v3.3._
                 */
                function functionStaticCall(
                    address target,
                    bytes memory data,
                    string memory errorMessage
                ) internal view returns (bytes memory) {
                    (bool success, bytes memory returndata) = target.staticcall(data);
                    return verifyCallResultFromTarget(target, success, returndata, errorMessage);
                }
                /**
                 * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                 * but performing a delegate call.
                 *
                 * _Available since v3.4._
                 */
                function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
                    return functionDelegateCall(target, data, "Address: low-level delegate call failed");
                }
                /**
                 * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                 * but performing a delegate call.
                 *
                 * _Available since v3.4._
                 */
                function functionDelegateCall(
                    address target,
                    bytes memory data,
                    string memory errorMessage
                ) internal returns (bytes memory) {
                    (bool success, bytes memory returndata) = target.delegatecall(data);
                    return verifyCallResultFromTarget(target, success, returndata, errorMessage);
                }
                /**
                 * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
                 * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
                 *
                 * _Available since v4.8._
                 */
                function verifyCallResultFromTarget(
                    address target,
                    bool success,
                    bytes memory returndata,
                    string memory errorMessage
                ) internal view returns (bytes memory) {
                    if (success) {
                        if (returndata.length == 0) {
                            // only check isContract if the call was successful and the return data is empty
                            // otherwise we already know that it was a contract
                            require(isContract(target), "Address: call to non-contract");
                        }
                        return returndata;
                    } else {
                        _revert(returndata, errorMessage);
                    }
                }
                /**
                 * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
                 * revert reason or using the provided one.
                 *
                 * _Available since v4.3._
                 */
                function verifyCallResult(
                    bool success,
                    bytes memory returndata,
                    string memory errorMessage
                ) internal pure returns (bytes memory) {
                    if (success) {
                        return returndata;
                    } else {
                        _revert(returndata, errorMessage);
                    }
                }
                function _revert(bytes memory returndata, string memory errorMessage) private pure {
                    // Look for revert reason and bubble it up if present
                    if (returndata.length > 0) {
                        // The easiest way to bubble the revert reason is using memory via assembly
                        /// @solidity memory-safe-assembly
                        assembly {
                            let returndata_size := mload(returndata)
                            revert(add(32, returndata), returndata_size)
                        }
                    } else {
                        revert(errorMessage);
                    }
                }
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.9.4) (utils/Context.sol)
            pragma solidity ^0.8.0;
            import {Initializable} from "../proxy/utils/Initializable.sol";
            /**
             * @dev Provides information about the current execution context, including the
             * sender of the transaction and its data. While these are generally available
             * via msg.sender and msg.data, they should not be accessed in such a direct
             * manner, since when dealing with meta-transactions the account sending and
             * paying for execution may not be the actual sender (as far as an application
             * is concerned).
             *
             * This contract is only required for intermediate, library-like contracts.
             */
            abstract contract ContextUpgradeable is Initializable {
                function __Context_init() internal onlyInitializing {
                }
                function __Context_init_unchained() internal onlyInitializing {
                }
                function _msgSender() internal view virtual returns (address) {
                    return msg.sender;
                }
                function _msgData() internal view virtual returns (bytes calldata) {
                    return msg.data;
                }
                function _contextSuffixLength() internal view virtual returns (uint256) {
                    return 0;
                }
                /**
                 * @dev This empty reserved space is put in place to allow future versions to add new
                 * variables without shifting down storage in the inheritance chain.
                 * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
                 */
                uint256[50] private __gap;
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
            pragma solidity ^0.8.0;
            import "./IERC165Upgradeable.sol";
            import {Initializable} from "../../proxy/utils/Initializable.sol";
            /**
             * @dev Implementation of the {IERC165} interface.
             *
             * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
             * for the additional interface id that will be supported. For example:
             *
             * ```solidity
             * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
             *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
             * }
             * ```
             *
             * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
             */
            abstract contract ERC165Upgradeable is Initializable, IERC165Upgradeable {
                function __ERC165_init() internal onlyInitializing {
                }
                function __ERC165_init_unchained() internal onlyInitializing {
                }
                /**
                 * @dev See {IERC165-supportsInterface}.
                 */
                function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
                    return interfaceId == type(IERC165Upgradeable).interfaceId;
                }
                /**
                 * @dev This empty reserved space is put in place to allow future versions to add new
                 * variables without shifting down storage in the inheritance chain.
                 * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
                 */
                uint256[50] private __gap;
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
            pragma solidity ^0.8.0;
            /**
             * @dev Interface of the ERC165 standard, as defined in the
             * https://eips.ethereum.org/EIPS/eip-165[EIP].
             *
             * Implementers can declare support of contract interfaces, which can then be
             * queried by others ({ERC165Checker}).
             *
             * For an implementation, see {ERC165}.
             */
            interface IERC165Upgradeable {
                /**
                 * @dev Returns true if this contract implements the interface defined by
                 * `interfaceId`. See the corresponding
                 * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
                 * to learn more about how these ids are created.
                 *
                 * This function call must use less than 30 000 gas.
                 */
                function supportsInterface(bytes4 interfaceId) external view returns (bool);
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.9.0) (utils/math/Math.sol)
            pragma solidity ^0.8.0;
            /**
             * @dev Standard math utilities missing in the Solidity language.
             */
            library MathUpgradeable {
                enum Rounding {
                    Down, // Toward negative infinity
                    Up, // Toward infinity
                    Zero // Toward zero
                }
                /**
                 * @dev Returns the largest of two numbers.
                 */
                function max(uint256 a, uint256 b) internal pure returns (uint256) {
                    return a > b ? a : b;
                }
                /**
                 * @dev Returns the smallest of two numbers.
                 */
                function min(uint256 a, uint256 b) internal pure returns (uint256) {
                    return a < b ? a : b;
                }
                /**
                 * @dev Returns the average of two numbers. The result is rounded towards
                 * zero.
                 */
                function average(uint256 a, uint256 b) internal pure returns (uint256) {
                    // (a + b) / 2 can overflow.
                    return (a & b) + (a ^ b) / 2;
                }
                /**
                 * @dev Returns the ceiling of the division of two numbers.
                 *
                 * This differs from standard division with `/` in that it rounds up instead
                 * of rounding down.
                 */
                function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
                    // (a + b - 1) / b can overflow on addition, so we distribute.
                    return a == 0 ? 0 : (a - 1) / b + 1;
                }
                /**
                 * @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
                 * @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
                 * with further edits by Uniswap Labs also under MIT license.
                 */
                function mulDiv(uint256 x, uint256 y, uint256 denominator) internal pure returns (uint256 result) {
                    unchecked {
                        // 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
                        // use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
                        // variables such that product = prod1 * 2^256 + prod0.
                        uint256 prod0; // Least significant 256 bits of the product
                        uint256 prod1; // Most significant 256 bits of the product
                        assembly {
                            let mm := mulmod(x, y, not(0))
                            prod0 := mul(x, y)
                            prod1 := sub(sub(mm, prod0), lt(mm, prod0))
                        }
                        // Handle non-overflow cases, 256 by 256 division.
                        if (prod1 == 0) {
                            // Solidity will revert if denominator == 0, unlike the div opcode on its own.
                            // The surrounding unchecked block does not change this fact.
                            // See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
                            return prod0 / denominator;
                        }
                        // Make sure the result is less than 2^256. Also prevents denominator == 0.
                        require(denominator > prod1, "Math: mulDiv overflow");
                        ///////////////////////////////////////////////
                        // 512 by 256 division.
                        ///////////////////////////////////////////////
                        // Make division exact by subtracting the remainder from [prod1 prod0].
                        uint256 remainder;
                        assembly {
                            // Compute remainder using mulmod.
                            remainder := mulmod(x, y, denominator)
                            // Subtract 256 bit number from 512 bit number.
                            prod1 := sub(prod1, gt(remainder, prod0))
                            prod0 := sub(prod0, remainder)
                        }
                        // Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
                        // See https://cs.stackexchange.com/q/138556/92363.
                        // Does not overflow because the denominator cannot be zero at this stage in the function.
                        uint256 twos = denominator & (~denominator + 1);
                        assembly {
                            // Divide denominator by twos.
                            denominator := div(denominator, twos)
                            // Divide [prod1 prod0] by twos.
                            prod0 := div(prod0, twos)
                            // Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
                            twos := add(div(sub(0, twos), twos), 1)
                        }
                        // Shift in bits from prod1 into prod0.
                        prod0 |= prod1 * twos;
                        // Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
                        // that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
                        // four bits. That is, denominator * inv = 1 mod 2^4.
                        uint256 inverse = (3 * denominator) ^ 2;
                        // Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
                        // in modular arithmetic, doubling the correct bits in each step.
                        inverse *= 2 - denominator * inverse; // inverse mod 2^8
                        inverse *= 2 - denominator * inverse; // inverse mod 2^16
                        inverse *= 2 - denominator * inverse; // inverse mod 2^32
                        inverse *= 2 - denominator * inverse; // inverse mod 2^64
                        inverse *= 2 - denominator * inverse; // inverse mod 2^128
                        inverse *= 2 - denominator * inverse; // inverse mod 2^256
                        // Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
                        // This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
                        // less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
                        // is no longer required.
                        result = prod0 * inverse;
                        return result;
                    }
                }
                /**
                 * @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
                 */
                function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
                    uint256 result = mulDiv(x, y, denominator);
                    if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
                        result += 1;
                    }
                    return result;
                }
                /**
                 * @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
                 *
                 * Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
                 */
                function sqrt(uint256 a) internal pure returns (uint256) {
                    if (a == 0) {
                        return 0;
                    }
                    // For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
                    //
                    // We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
                    // `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
                    //
                    // This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
                    // → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
                    // → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
                    //
                    // Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
                    uint256 result = 1 << (log2(a) >> 1);
                    // At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
                    // since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
                    // every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
                    // into the expected uint128 result.
                    unchecked {
                        result = (result + a / result) >> 1;
                        result = (result + a / result) >> 1;
                        result = (result + a / result) >> 1;
                        result = (result + a / result) >> 1;
                        result = (result + a / result) >> 1;
                        result = (result + a / result) >> 1;
                        result = (result + a / result) >> 1;
                        return min(result, a / result);
                    }
                }
                /**
                 * @notice Calculates sqrt(a), following the selected rounding direction.
                 */
                function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
                    unchecked {
                        uint256 result = sqrt(a);
                        return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
                    }
                }
                /**
                 * @dev Return the log in base 2, rounded down, of a positive value.
                 * Returns 0 if given 0.
                 */
                function log2(uint256 value) internal pure returns (uint256) {
                    uint256 result = 0;
                    unchecked {
                        if (value >> 128 > 0) {
                            value >>= 128;
                            result += 128;
                        }
                        if (value >> 64 > 0) {
                            value >>= 64;
                            result += 64;
                        }
                        if (value >> 32 > 0) {
                            value >>= 32;
                            result += 32;
                        }
                        if (value >> 16 > 0) {
                            value >>= 16;
                            result += 16;
                        }
                        if (value >> 8 > 0) {
                            value >>= 8;
                            result += 8;
                        }
                        if (value >> 4 > 0) {
                            value >>= 4;
                            result += 4;
                        }
                        if (value >> 2 > 0) {
                            value >>= 2;
                            result += 2;
                        }
                        if (value >> 1 > 0) {
                            result += 1;
                        }
                    }
                    return result;
                }
                /**
                 * @dev Return the log in base 2, following the selected rounding direction, of a positive value.
                 * Returns 0 if given 0.
                 */
                function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
                    unchecked {
                        uint256 result = log2(value);
                        return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
                    }
                }
                /**
                 * @dev Return the log in base 10, rounded down, of a positive value.
                 * Returns 0 if given 0.
                 */
                function log10(uint256 value) internal pure returns (uint256) {
                    uint256 result = 0;
                    unchecked {
                        if (value >= 10 ** 64) {
                            value /= 10 ** 64;
                            result += 64;
                        }
                        if (value >= 10 ** 32) {
                            value /= 10 ** 32;
                            result += 32;
                        }
                        if (value >= 10 ** 16) {
                            value /= 10 ** 16;
                            result += 16;
                        }
                        if (value >= 10 ** 8) {
                            value /= 10 ** 8;
                            result += 8;
                        }
                        if (value >= 10 ** 4) {
                            value /= 10 ** 4;
                            result += 4;
                        }
                        if (value >= 10 ** 2) {
                            value /= 10 ** 2;
                            result += 2;
                        }
                        if (value >= 10 ** 1) {
                            result += 1;
                        }
                    }
                    return result;
                }
                /**
                 * @dev Return the log in base 10, following the selected rounding direction, of a positive value.
                 * Returns 0 if given 0.
                 */
                function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
                    unchecked {
                        uint256 result = log10(value);
                        return result + (rounding == Rounding.Up && 10 ** result < value ? 1 : 0);
                    }
                }
                /**
                 * @dev Return the log in base 256, rounded down, of a positive value.
                 * Returns 0 if given 0.
                 *
                 * Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
                 */
                function log256(uint256 value) internal pure returns (uint256) {
                    uint256 result = 0;
                    unchecked {
                        if (value >> 128 > 0) {
                            value >>= 128;
                            result += 16;
                        }
                        if (value >> 64 > 0) {
                            value >>= 64;
                            result += 8;
                        }
                        if (value >> 32 > 0) {
                            value >>= 32;
                            result += 4;
                        }
                        if (value >> 16 > 0) {
                            value >>= 16;
                            result += 2;
                        }
                        if (value >> 8 > 0) {
                            result += 1;
                        }
                    }
                    return result;
                }
                /**
                 * @dev Return the log in base 256, following the selected rounding direction, of a positive value.
                 * Returns 0 if given 0.
                 */
                function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
                    unchecked {
                        uint256 result = log256(value);
                        return result + (rounding == Rounding.Up && 1 << (result << 3) < value ? 1 : 0);
                    }
                }
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.8.0) (utils/math/SafeCast.sol)
            // This file was procedurally generated from scripts/generate/templates/SafeCast.js.
            pragma solidity ^0.8.0;
            /**
             * @dev Wrappers over Solidity's uintXX/intXX casting operators with added overflow
             * checks.
             *
             * Downcasting from uint256/int256 in Solidity does not revert on overflow. This can
             * easily result in undesired exploitation or bugs, since developers usually
             * assume that overflows raise errors. `SafeCast` restores this intuition by
             * reverting the transaction when such an operation overflows.
             *
             * Using this library instead of the unchecked operations eliminates an entire
             * class of bugs, so it's recommended to use it always.
             *
             * Can be combined with {SafeMath} and {SignedSafeMath} to extend it to smaller types, by performing
             * all math on `uint256` and `int256` and then downcasting.
             */
            library SafeCastUpgradeable {
                /**
                 * @dev Returns the downcasted uint248 from uint256, reverting on
                 * overflow (when the input is greater than largest uint248).
                 *
                 * Counterpart to Solidity's `uint248` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 248 bits
                 *
                 * _Available since v4.7._
                 */
                function toUint248(uint256 value) internal pure returns (uint248) {
                    require(value <= type(uint248).max, "SafeCast: value doesn't fit in 248 bits");
                    return uint248(value);
                }
                /**
                 * @dev Returns the downcasted uint240 from uint256, reverting on
                 * overflow (when the input is greater than largest uint240).
                 *
                 * Counterpart to Solidity's `uint240` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 240 bits
                 *
                 * _Available since v4.7._
                 */
                function toUint240(uint256 value) internal pure returns (uint240) {
                    require(value <= type(uint240).max, "SafeCast: value doesn't fit in 240 bits");
                    return uint240(value);
                }
                /**
                 * @dev Returns the downcasted uint232 from uint256, reverting on
                 * overflow (when the input is greater than largest uint232).
                 *
                 * Counterpart to Solidity's `uint232` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 232 bits
                 *
                 * _Available since v4.7._
                 */
                function toUint232(uint256 value) internal pure returns (uint232) {
                    require(value <= type(uint232).max, "SafeCast: value doesn't fit in 232 bits");
                    return uint232(value);
                }
                /**
                 * @dev Returns the downcasted uint224 from uint256, reverting on
                 * overflow (when the input is greater than largest uint224).
                 *
                 * Counterpart to Solidity's `uint224` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 224 bits
                 *
                 * _Available since v4.2._
                 */
                function toUint224(uint256 value) internal pure returns (uint224) {
                    require(value <= type(uint224).max, "SafeCast: value doesn't fit in 224 bits");
                    return uint224(value);
                }
                /**
                 * @dev Returns the downcasted uint216 from uint256, reverting on
                 * overflow (when the input is greater than largest uint216).
                 *
                 * Counterpart to Solidity's `uint216` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 216 bits
                 *
                 * _Available since v4.7._
                 */
                function toUint216(uint256 value) internal pure returns (uint216) {
                    require(value <= type(uint216).max, "SafeCast: value doesn't fit in 216 bits");
                    return uint216(value);
                }
                /**
                 * @dev Returns the downcasted uint208 from uint256, reverting on
                 * overflow (when the input is greater than largest uint208).
                 *
                 * Counterpart to Solidity's `uint208` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 208 bits
                 *
                 * _Available since v4.7._
                 */
                function toUint208(uint256 value) internal pure returns (uint208) {
                    require(value <= type(uint208).max, "SafeCast: value doesn't fit in 208 bits");
                    return uint208(value);
                }
                /**
                 * @dev Returns the downcasted uint200 from uint256, reverting on
                 * overflow (when the input is greater than largest uint200).
                 *
                 * Counterpart to Solidity's `uint200` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 200 bits
                 *
                 * _Available since v4.7._
                 */
                function toUint200(uint256 value) internal pure returns (uint200) {
                    require(value <= type(uint200).max, "SafeCast: value doesn't fit in 200 bits");
                    return uint200(value);
                }
                /**
                 * @dev Returns the downcasted uint192 from uint256, reverting on
                 * overflow (when the input is greater than largest uint192).
                 *
                 * Counterpart to Solidity's `uint192` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 192 bits
                 *
                 * _Available since v4.7._
                 */
                function toUint192(uint256 value) internal pure returns (uint192) {
                    require(value <= type(uint192).max, "SafeCast: value doesn't fit in 192 bits");
                    return uint192(value);
                }
                /**
                 * @dev Returns the downcasted uint184 from uint256, reverting on
                 * overflow (when the input is greater than largest uint184).
                 *
                 * Counterpart to Solidity's `uint184` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 184 bits
                 *
                 * _Available since v4.7._
                 */
                function toUint184(uint256 value) internal pure returns (uint184) {
                    require(value <= type(uint184).max, "SafeCast: value doesn't fit in 184 bits");
                    return uint184(value);
                }
                /**
                 * @dev Returns the downcasted uint176 from uint256, reverting on
                 * overflow (when the input is greater than largest uint176).
                 *
                 * Counterpart to Solidity's `uint176` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 176 bits
                 *
                 * _Available since v4.7._
                 */
                function toUint176(uint256 value) internal pure returns (uint176) {
                    require(value <= type(uint176).max, "SafeCast: value doesn't fit in 176 bits");
                    return uint176(value);
                }
                /**
                 * @dev Returns the downcasted uint168 from uint256, reverting on
                 * overflow (when the input is greater than largest uint168).
                 *
                 * Counterpart to Solidity's `uint168` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 168 bits
                 *
                 * _Available since v4.7._
                 */
                function toUint168(uint256 value) internal pure returns (uint168) {
                    require(value <= type(uint168).max, "SafeCast: value doesn't fit in 168 bits");
                    return uint168(value);
                }
                /**
                 * @dev Returns the downcasted uint160 from uint256, reverting on
                 * overflow (when the input is greater than largest uint160).
                 *
                 * Counterpart to Solidity's `uint160` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 160 bits
                 *
                 * _Available since v4.7._
                 */
                function toUint160(uint256 value) internal pure returns (uint160) {
                    require(value <= type(uint160).max, "SafeCast: value doesn't fit in 160 bits");
                    return uint160(value);
                }
                /**
                 * @dev Returns the downcasted uint152 from uint256, reverting on
                 * overflow (when the input is greater than largest uint152).
                 *
                 * Counterpart to Solidity's `uint152` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 152 bits
                 *
                 * _Available since v4.7._
                 */
                function toUint152(uint256 value) internal pure returns (uint152) {
                    require(value <= type(uint152).max, "SafeCast: value doesn't fit in 152 bits");
                    return uint152(value);
                }
                /**
                 * @dev Returns the downcasted uint144 from uint256, reverting on
                 * overflow (when the input is greater than largest uint144).
                 *
                 * Counterpart to Solidity's `uint144` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 144 bits
                 *
                 * _Available since v4.7._
                 */
                function toUint144(uint256 value) internal pure returns (uint144) {
                    require(value <= type(uint144).max, "SafeCast: value doesn't fit in 144 bits");
                    return uint144(value);
                }
                /**
                 * @dev Returns the downcasted uint136 from uint256, reverting on
                 * overflow (when the input is greater than largest uint136).
                 *
                 * Counterpart to Solidity's `uint136` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 136 bits
                 *
                 * _Available since v4.7._
                 */
                function toUint136(uint256 value) internal pure returns (uint136) {
                    require(value <= type(uint136).max, "SafeCast: value doesn't fit in 136 bits");
                    return uint136(value);
                }
                /**
                 * @dev Returns the downcasted uint128 from uint256, reverting on
                 * overflow (when the input is greater than largest uint128).
                 *
                 * Counterpart to Solidity's `uint128` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 128 bits
                 *
                 * _Available since v2.5._
                 */
                function toUint128(uint256 value) internal pure returns (uint128) {
                    require(value <= type(uint128).max, "SafeCast: value doesn't fit in 128 bits");
                    return uint128(value);
                }
                /**
                 * @dev Returns the downcasted uint120 from uint256, reverting on
                 * overflow (when the input is greater than largest uint120).
                 *
                 * Counterpart to Solidity's `uint120` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 120 bits
                 *
                 * _Available since v4.7._
                 */
                function toUint120(uint256 value) internal pure returns (uint120) {
                    require(value <= type(uint120).max, "SafeCast: value doesn't fit in 120 bits");
                    return uint120(value);
                }
                /**
                 * @dev Returns the downcasted uint112 from uint256, reverting on
                 * overflow (when the input is greater than largest uint112).
                 *
                 * Counterpart to Solidity's `uint112` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 112 bits
                 *
                 * _Available since v4.7._
                 */
                function toUint112(uint256 value) internal pure returns (uint112) {
                    require(value <= type(uint112).max, "SafeCast: value doesn't fit in 112 bits");
                    return uint112(value);
                }
                /**
                 * @dev Returns the downcasted uint104 from uint256, reverting on
                 * overflow (when the input is greater than largest uint104).
                 *
                 * Counterpart to Solidity's `uint104` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 104 bits
                 *
                 * _Available since v4.7._
                 */
                function toUint104(uint256 value) internal pure returns (uint104) {
                    require(value <= type(uint104).max, "SafeCast: value doesn't fit in 104 bits");
                    return uint104(value);
                }
                /**
                 * @dev Returns the downcasted uint96 from uint256, reverting on
                 * overflow (when the input is greater than largest uint96).
                 *
                 * Counterpart to Solidity's `uint96` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 96 bits
                 *
                 * _Available since v4.2._
                 */
                function toUint96(uint256 value) internal pure returns (uint96) {
                    require(value <= type(uint96).max, "SafeCast: value doesn't fit in 96 bits");
                    return uint96(value);
                }
                /**
                 * @dev Returns the downcasted uint88 from uint256, reverting on
                 * overflow (when the input is greater than largest uint88).
                 *
                 * Counterpart to Solidity's `uint88` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 88 bits
                 *
                 * _Available since v4.7._
                 */
                function toUint88(uint256 value) internal pure returns (uint88) {
                    require(value <= type(uint88).max, "SafeCast: value doesn't fit in 88 bits");
                    return uint88(value);
                }
                /**
                 * @dev Returns the downcasted uint80 from uint256, reverting on
                 * overflow (when the input is greater than largest uint80).
                 *
                 * Counterpart to Solidity's `uint80` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 80 bits
                 *
                 * _Available since v4.7._
                 */
                function toUint80(uint256 value) internal pure returns (uint80) {
                    require(value <= type(uint80).max, "SafeCast: value doesn't fit in 80 bits");
                    return uint80(value);
                }
                /**
                 * @dev Returns the downcasted uint72 from uint256, reverting on
                 * overflow (when the input is greater than largest uint72).
                 *
                 * Counterpart to Solidity's `uint72` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 72 bits
                 *
                 * _Available since v4.7._
                 */
                function toUint72(uint256 value) internal pure returns (uint72) {
                    require(value <= type(uint72).max, "SafeCast: value doesn't fit in 72 bits");
                    return uint72(value);
                }
                /**
                 * @dev Returns the downcasted uint64 from uint256, reverting on
                 * overflow (when the input is greater than largest uint64).
                 *
                 * Counterpart to Solidity's `uint64` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 64 bits
                 *
                 * _Available since v2.5._
                 */
                function toUint64(uint256 value) internal pure returns (uint64) {
                    require(value <= type(uint64).max, "SafeCast: value doesn't fit in 64 bits");
                    return uint64(value);
                }
                /**
                 * @dev Returns the downcasted uint56 from uint256, reverting on
                 * overflow (when the input is greater than largest uint56).
                 *
                 * Counterpart to Solidity's `uint56` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 56 bits
                 *
                 * _Available since v4.7._
                 */
                function toUint56(uint256 value) internal pure returns (uint56) {
                    require(value <= type(uint56).max, "SafeCast: value doesn't fit in 56 bits");
                    return uint56(value);
                }
                /**
                 * @dev Returns the downcasted uint48 from uint256, reverting on
                 * overflow (when the input is greater than largest uint48).
                 *
                 * Counterpart to Solidity's `uint48` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 48 bits
                 *
                 * _Available since v4.7._
                 */
                function toUint48(uint256 value) internal pure returns (uint48) {
                    require(value <= type(uint48).max, "SafeCast: value doesn't fit in 48 bits");
                    return uint48(value);
                }
                /**
                 * @dev Returns the downcasted uint40 from uint256, reverting on
                 * overflow (when the input is greater than largest uint40).
                 *
                 * Counterpart to Solidity's `uint40` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 40 bits
                 *
                 * _Available since v4.7._
                 */
                function toUint40(uint256 value) internal pure returns (uint40) {
                    require(value <= type(uint40).max, "SafeCast: value doesn't fit in 40 bits");
                    return uint40(value);
                }
                /**
                 * @dev Returns the downcasted uint32 from uint256, reverting on
                 * overflow (when the input is greater than largest uint32).
                 *
                 * Counterpart to Solidity's `uint32` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 32 bits
                 *
                 * _Available since v2.5._
                 */
                function toUint32(uint256 value) internal pure returns (uint32) {
                    require(value <= type(uint32).max, "SafeCast: value doesn't fit in 32 bits");
                    return uint32(value);
                }
                /**
                 * @dev Returns the downcasted uint24 from uint256, reverting on
                 * overflow (when the input is greater than largest uint24).
                 *
                 * Counterpart to Solidity's `uint24` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 24 bits
                 *
                 * _Available since v4.7._
                 */
                function toUint24(uint256 value) internal pure returns (uint24) {
                    require(value <= type(uint24).max, "SafeCast: value doesn't fit in 24 bits");
                    return uint24(value);
                }
                /**
                 * @dev Returns the downcasted uint16 from uint256, reverting on
                 * overflow (when the input is greater than largest uint16).
                 *
                 * Counterpart to Solidity's `uint16` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 16 bits
                 *
                 * _Available since v2.5._
                 */
                function toUint16(uint256 value) internal pure returns (uint16) {
                    require(value <= type(uint16).max, "SafeCast: value doesn't fit in 16 bits");
                    return uint16(value);
                }
                /**
                 * @dev Returns the downcasted uint8 from uint256, reverting on
                 * overflow (when the input is greater than largest uint8).
                 *
                 * Counterpart to Solidity's `uint8` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 8 bits
                 *
                 * _Available since v2.5._
                 */
                function toUint8(uint256 value) internal pure returns (uint8) {
                    require(value <= type(uint8).max, "SafeCast: value doesn't fit in 8 bits");
                    return uint8(value);
                }
                /**
                 * @dev Converts a signed int256 into an unsigned uint256.
                 *
                 * Requirements:
                 *
                 * - input must be greater than or equal to 0.
                 *
                 * _Available since v3.0._
                 */
                function toUint256(int256 value) internal pure returns (uint256) {
                    require(value >= 0, "SafeCast: value must be positive");
                    return uint256(value);
                }
                /**
                 * @dev Returns the downcasted int248 from int256, reverting on
                 * overflow (when the input is less than smallest int248 or
                 * greater than largest int248).
                 *
                 * Counterpart to Solidity's `int248` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 248 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt248(int256 value) internal pure returns (int248 downcasted) {
                    downcasted = int248(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 248 bits");
                }
                /**
                 * @dev Returns the downcasted int240 from int256, reverting on
                 * overflow (when the input is less than smallest int240 or
                 * greater than largest int240).
                 *
                 * Counterpart to Solidity's `int240` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 240 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt240(int256 value) internal pure returns (int240 downcasted) {
                    downcasted = int240(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 240 bits");
                }
                /**
                 * @dev Returns the downcasted int232 from int256, reverting on
                 * overflow (when the input is less than smallest int232 or
                 * greater than largest int232).
                 *
                 * Counterpart to Solidity's `int232` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 232 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt232(int256 value) internal pure returns (int232 downcasted) {
                    downcasted = int232(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 232 bits");
                }
                /**
                 * @dev Returns the downcasted int224 from int256, reverting on
                 * overflow (when the input is less than smallest int224 or
                 * greater than largest int224).
                 *
                 * Counterpart to Solidity's `int224` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 224 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt224(int256 value) internal pure returns (int224 downcasted) {
                    downcasted = int224(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 224 bits");
                }
                /**
                 * @dev Returns the downcasted int216 from int256, reverting on
                 * overflow (when the input is less than smallest int216 or
                 * greater than largest int216).
                 *
                 * Counterpart to Solidity's `int216` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 216 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt216(int256 value) internal pure returns (int216 downcasted) {
                    downcasted = int216(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 216 bits");
                }
                /**
                 * @dev Returns the downcasted int208 from int256, reverting on
                 * overflow (when the input is less than smallest int208 or
                 * greater than largest int208).
                 *
                 * Counterpart to Solidity's `int208` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 208 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt208(int256 value) internal pure returns (int208 downcasted) {
                    downcasted = int208(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 208 bits");
                }
                /**
                 * @dev Returns the downcasted int200 from int256, reverting on
                 * overflow (when the input is less than smallest int200 or
                 * greater than largest int200).
                 *
                 * Counterpart to Solidity's `int200` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 200 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt200(int256 value) internal pure returns (int200 downcasted) {
                    downcasted = int200(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 200 bits");
                }
                /**
                 * @dev Returns the downcasted int192 from int256, reverting on
                 * overflow (when the input is less than smallest int192 or
                 * greater than largest int192).
                 *
                 * Counterpart to Solidity's `int192` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 192 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt192(int256 value) internal pure returns (int192 downcasted) {
                    downcasted = int192(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 192 bits");
                }
                /**
                 * @dev Returns the downcasted int184 from int256, reverting on
                 * overflow (when the input is less than smallest int184 or
                 * greater than largest int184).
                 *
                 * Counterpart to Solidity's `int184` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 184 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt184(int256 value) internal pure returns (int184 downcasted) {
                    downcasted = int184(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 184 bits");
                }
                /**
                 * @dev Returns the downcasted int176 from int256, reverting on
                 * overflow (when the input is less than smallest int176 or
                 * greater than largest int176).
                 *
                 * Counterpart to Solidity's `int176` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 176 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt176(int256 value) internal pure returns (int176 downcasted) {
                    downcasted = int176(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 176 bits");
                }
                /**
                 * @dev Returns the downcasted int168 from int256, reverting on
                 * overflow (when the input is less than smallest int168 or
                 * greater than largest int168).
                 *
                 * Counterpart to Solidity's `int168` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 168 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt168(int256 value) internal pure returns (int168 downcasted) {
                    downcasted = int168(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 168 bits");
                }
                /**
                 * @dev Returns the downcasted int160 from int256, reverting on
                 * overflow (when the input is less than smallest int160 or
                 * greater than largest int160).
                 *
                 * Counterpart to Solidity's `int160` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 160 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt160(int256 value) internal pure returns (int160 downcasted) {
                    downcasted = int160(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 160 bits");
                }
                /**
                 * @dev Returns the downcasted int152 from int256, reverting on
                 * overflow (when the input is less than smallest int152 or
                 * greater than largest int152).
                 *
                 * Counterpart to Solidity's `int152` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 152 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt152(int256 value) internal pure returns (int152 downcasted) {
                    downcasted = int152(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 152 bits");
                }
                /**
                 * @dev Returns the downcasted int144 from int256, reverting on
                 * overflow (when the input is less than smallest int144 or
                 * greater than largest int144).
                 *
                 * Counterpart to Solidity's `int144` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 144 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt144(int256 value) internal pure returns (int144 downcasted) {
                    downcasted = int144(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 144 bits");
                }
                /**
                 * @dev Returns the downcasted int136 from int256, reverting on
                 * overflow (when the input is less than smallest int136 or
                 * greater than largest int136).
                 *
                 * Counterpart to Solidity's `int136` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 136 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt136(int256 value) internal pure returns (int136 downcasted) {
                    downcasted = int136(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 136 bits");
                }
                /**
                 * @dev Returns the downcasted int128 from int256, reverting on
                 * overflow (when the input is less than smallest int128 or
                 * greater than largest int128).
                 *
                 * Counterpart to Solidity's `int128` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 128 bits
                 *
                 * _Available since v3.1._
                 */
                function toInt128(int256 value) internal pure returns (int128 downcasted) {
                    downcasted = int128(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 128 bits");
                }
                /**
                 * @dev Returns the downcasted int120 from int256, reverting on
                 * overflow (when the input is less than smallest int120 or
                 * greater than largest int120).
                 *
                 * Counterpart to Solidity's `int120` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 120 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt120(int256 value) internal pure returns (int120 downcasted) {
                    downcasted = int120(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 120 bits");
                }
                /**
                 * @dev Returns the downcasted int112 from int256, reverting on
                 * overflow (when the input is less than smallest int112 or
                 * greater than largest int112).
                 *
                 * Counterpart to Solidity's `int112` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 112 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt112(int256 value) internal pure returns (int112 downcasted) {
                    downcasted = int112(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 112 bits");
                }
                /**
                 * @dev Returns the downcasted int104 from int256, reverting on
                 * overflow (when the input is less than smallest int104 or
                 * greater than largest int104).
                 *
                 * Counterpart to Solidity's `int104` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 104 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt104(int256 value) internal pure returns (int104 downcasted) {
                    downcasted = int104(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 104 bits");
                }
                /**
                 * @dev Returns the downcasted int96 from int256, reverting on
                 * overflow (when the input is less than smallest int96 or
                 * greater than largest int96).
                 *
                 * Counterpart to Solidity's `int96` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 96 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt96(int256 value) internal pure returns (int96 downcasted) {
                    downcasted = int96(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 96 bits");
                }
                /**
                 * @dev Returns the downcasted int88 from int256, reverting on
                 * overflow (when the input is less than smallest int88 or
                 * greater than largest int88).
                 *
                 * Counterpart to Solidity's `int88` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 88 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt88(int256 value) internal pure returns (int88 downcasted) {
                    downcasted = int88(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 88 bits");
                }
                /**
                 * @dev Returns the downcasted int80 from int256, reverting on
                 * overflow (when the input is less than smallest int80 or
                 * greater than largest int80).
                 *
                 * Counterpart to Solidity's `int80` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 80 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt80(int256 value) internal pure returns (int80 downcasted) {
                    downcasted = int80(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 80 bits");
                }
                /**
                 * @dev Returns the downcasted int72 from int256, reverting on
                 * overflow (when the input is less than smallest int72 or
                 * greater than largest int72).
                 *
                 * Counterpart to Solidity's `int72` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 72 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt72(int256 value) internal pure returns (int72 downcasted) {
                    downcasted = int72(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 72 bits");
                }
                /**
                 * @dev Returns the downcasted int64 from int256, reverting on
                 * overflow (when the input is less than smallest int64 or
                 * greater than largest int64).
                 *
                 * Counterpart to Solidity's `int64` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 64 bits
                 *
                 * _Available since v3.1._
                 */
                function toInt64(int256 value) internal pure returns (int64 downcasted) {
                    downcasted = int64(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 64 bits");
                }
                /**
                 * @dev Returns the downcasted int56 from int256, reverting on
                 * overflow (when the input is less than smallest int56 or
                 * greater than largest int56).
                 *
                 * Counterpart to Solidity's `int56` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 56 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt56(int256 value) internal pure returns (int56 downcasted) {
                    downcasted = int56(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 56 bits");
                }
                /**
                 * @dev Returns the downcasted int48 from int256, reverting on
                 * overflow (when the input is less than smallest int48 or
                 * greater than largest int48).
                 *
                 * Counterpart to Solidity's `int48` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 48 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt48(int256 value) internal pure returns (int48 downcasted) {
                    downcasted = int48(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 48 bits");
                }
                /**
                 * @dev Returns the downcasted int40 from int256, reverting on
                 * overflow (when the input is less than smallest int40 or
                 * greater than largest int40).
                 *
                 * Counterpart to Solidity's `int40` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 40 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt40(int256 value) internal pure returns (int40 downcasted) {
                    downcasted = int40(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 40 bits");
                }
                /**
                 * @dev Returns the downcasted int32 from int256, reverting on
                 * overflow (when the input is less than smallest int32 or
                 * greater than largest int32).
                 *
                 * Counterpart to Solidity's `int32` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 32 bits
                 *
                 * _Available since v3.1._
                 */
                function toInt32(int256 value) internal pure returns (int32 downcasted) {
                    downcasted = int32(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 32 bits");
                }
                /**
                 * @dev Returns the downcasted int24 from int256, reverting on
                 * overflow (when the input is less than smallest int24 or
                 * greater than largest int24).
                 *
                 * Counterpart to Solidity's `int24` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 24 bits
                 *
                 * _Available since v4.7._
                 */
                function toInt24(int256 value) internal pure returns (int24 downcasted) {
                    downcasted = int24(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 24 bits");
                }
                /**
                 * @dev Returns the downcasted int16 from int256, reverting on
                 * overflow (when the input is less than smallest int16 or
                 * greater than largest int16).
                 *
                 * Counterpart to Solidity's `int16` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 16 bits
                 *
                 * _Available since v3.1._
                 */
                function toInt16(int256 value) internal pure returns (int16 downcasted) {
                    downcasted = int16(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 16 bits");
                }
                /**
                 * @dev Returns the downcasted int8 from int256, reverting on
                 * overflow (when the input is less than smallest int8 or
                 * greater than largest int8).
                 *
                 * Counterpart to Solidity's `int8` operator.
                 *
                 * Requirements:
                 *
                 * - input must fit into 8 bits
                 *
                 * _Available since v3.1._
                 */
                function toInt8(int256 value) internal pure returns (int8 downcasted) {
                    downcasted = int8(value);
                    require(downcasted == value, "SafeCast: value doesn't fit in 8 bits");
                }
                /**
                 * @dev Converts an unsigned uint256 into a signed int256.
                 *
                 * Requirements:
                 *
                 * - input must be less than or equal to maxInt256.
                 *
                 * _Available since v3.0._
                 */
                function toInt256(uint256 value) internal pure returns (int256) {
                    // Note: Unsafe cast below is okay because `type(int256).max` is guaranteed to be positive
                    require(value <= uint256(type(int256).max), "SafeCast: value doesn't fit in an int256");
                    return int256(value);
                }
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.8.0) (utils/math/SignedMath.sol)
            pragma solidity ^0.8.0;
            /**
             * @dev Standard signed math utilities missing in the Solidity language.
             */
            library SignedMathUpgradeable {
                /**
                 * @dev Returns the largest of two signed numbers.
                 */
                function max(int256 a, int256 b) internal pure returns (int256) {
                    return a > b ? a : b;
                }
                /**
                 * @dev Returns the smallest of two signed numbers.
                 */
                function min(int256 a, int256 b) internal pure returns (int256) {
                    return a < b ? a : b;
                }
                /**
                 * @dev Returns the average of two signed numbers without overflow.
                 * The result is rounded towards zero.
                 */
                function average(int256 a, int256 b) internal pure returns (int256) {
                    // Formula from the book "Hacker's Delight"
                    int256 x = (a & b) + ((a ^ b) >> 1);
                    return x + (int256(uint256(x) >> 255) & (a ^ b));
                }
                /**
                 * @dev Returns the absolute unsigned value of a signed value.
                 */
                function abs(int256 n) internal pure returns (uint256) {
                    unchecked {
                        // must be unchecked in order to support `n = type(int256).min`
                        return uint256(n >= 0 ? n : -n);
                    }
                }
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.9.0) (utils/StorageSlot.sol)
            // This file was procedurally generated from scripts/generate/templates/StorageSlot.js.
            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:
             * ```solidity
             * 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`, `uint256`._
             * _Available since v4.9 for `string`, `bytes`._
             */
            library StorageSlotUpgradeable {
                struct AddressSlot {
                    address value;
                }
                struct BooleanSlot {
                    bool value;
                }
                struct Bytes32Slot {
                    bytes32 value;
                }
                struct Uint256Slot {
                    uint256 value;
                }
                struct StringSlot {
                    string value;
                }
                struct BytesSlot {
                    bytes value;
                }
                /**
                 * @dev Returns an `AddressSlot` with member `value` located at `slot`.
                 */
                function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
                    /// @solidity memory-safe-assembly
                    assembly {
                        r.slot := slot
                    }
                }
                /**
                 * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
                 */
                function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
                    /// @solidity memory-safe-assembly
                    assembly {
                        r.slot := slot
                    }
                }
                /**
                 * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
                 */
                function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
                    /// @solidity memory-safe-assembly
                    assembly {
                        r.slot := slot
                    }
                }
                /**
                 * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
                 */
                function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
                    /// @solidity memory-safe-assembly
                    assembly {
                        r.slot := slot
                    }
                }
                /**
                 * @dev Returns an `StringSlot` with member `value` located at `slot`.
                 */
                function getStringSlot(bytes32 slot) internal pure returns (StringSlot storage r) {
                    /// @solidity memory-safe-assembly
                    assembly {
                        r.slot := slot
                    }
                }
                /**
                 * @dev Returns an `StringSlot` representation of the string storage pointer `store`.
                 */
                function getStringSlot(string storage store) internal pure returns (StringSlot storage r) {
                    /// @solidity memory-safe-assembly
                    assembly {
                        r.slot := store.slot
                    }
                }
                /**
                 * @dev Returns an `BytesSlot` with member `value` located at `slot`.
                 */
                function getBytesSlot(bytes32 slot) internal pure returns (BytesSlot storage r) {
                    /// @solidity memory-safe-assembly
                    assembly {
                        r.slot := slot
                    }
                }
                /**
                 * @dev Returns an `BytesSlot` representation of the bytes storage pointer `store`.
                 */
                function getBytesSlot(bytes storage store) internal pure returns (BytesSlot storage r) {
                    /// @solidity memory-safe-assembly
                    assembly {
                        r.slot := store.slot
                    }
                }
            }
            // SPDX-License-Identifier: MIT
            // OpenZeppelin Contracts (last updated v4.9.0) (utils/Strings.sol)
            pragma solidity ^0.8.0;
            import "./math/MathUpgradeable.sol";
            import "./math/SignedMathUpgradeable.sol";
            /**
             * @dev String operations.
             */
            library StringsUpgradeable {
                bytes16 private constant _SYMBOLS = "0123456789abcdef";
                uint8 private constant _ADDRESS_LENGTH = 20;
                /**
                 * @dev Converts a `uint256` to its ASCII `string` decimal representation.
                 */
                function toString(uint256 value) internal pure returns (string memory) {
                    unchecked {
                        uint256 length = MathUpgradeable.log10(value) + 1;
                        string memory buffer = new string(length);
                        uint256 ptr;
                        /// @solidity memory-safe-assembly
                        assembly {
                            ptr := add(buffer, add(32, length))
                        }
                        while (true) {
                            ptr--;
                            /// @solidity memory-safe-assembly
                            assembly {
                                mstore8(ptr, byte(mod(value, 10), _SYMBOLS))
                            }
                            value /= 10;
                            if (value == 0) break;
                        }
                        return buffer;
                    }
                }
                /**
                 * @dev Converts a `int256` to its ASCII `string` decimal representation.
                 */
                function toString(int256 value) internal pure returns (string memory) {
                    return string(abi.encodePacked(value < 0 ? "-" : "", toString(SignedMathUpgradeable.abs(value))));
                }
                /**
                 * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
                 */
                function toHexString(uint256 value) internal pure returns (string memory) {
                    unchecked {
                        return toHexString(value, MathUpgradeable.log256(value) + 1);
                    }
                }
                /**
                 * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
                 */
                function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
                    bytes memory buffer = new bytes(2 * length + 2);
                    buffer[0] = "0";
                    buffer[1] = "x";
                    for (uint256 i = 2 * length + 1; i > 1; --i) {
                        buffer[i] = _SYMBOLS[value & 0xf];
                        value >>= 4;
                    }
                    require(value == 0, "Strings: hex length insufficient");
                    return string(buffer);
                }
                /**
                 * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
                 */
                function toHexString(address addr) internal pure returns (string memory) {
                    return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
                }
                /**
                 * @dev Returns true if the two strings are equal.
                 */
                function equal(string memory a, string memory b) internal pure returns (bool) {
                    return keccak256(bytes(a)) == keccak256(bytes(b));
                }
            }
            // SPDX-License-Identifier: MIT
            pragma solidity 0.8.17;
            /**
             * @title A library that provides a safe ECDSA recovery function
             * @custom:security-contact [email protected]
             */
            library ECRecover {
                error InvalidValueS();
                error InvalidSignature();
                /**
                 * @dev Recover signer's address from a signed message.
                 * Adapted from: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v4.8.0/contracts/utils/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. https://0xsomeone.medium.com/b002-solidity-ec-signature-pitfalls-b24a0f91aef4 proposes
                    // the valid range for s: 0 < s < secp256k1n ÷ 2 + 1, and for 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 InvalidValueS();
                    }
                    // If the signature is valid (and not malleable), return the signer address
                    address signer = ecrecover(digest, v, r, s);
                    if (signer == address(0)) revert InvalidSignature();
                    return signer;
                }
            }
            // SPDX-License-Identifier: MIT
            pragma solidity 0.8.17;
            import {PaxosBaseAbstract} from "./PaxosBaseAbstract.sol";
            import {EIP712} from "./EIP712.sol";
            /**
             * @title EIP2612 contract
             * @dev An abstract contract to provide EIP2612 functionality.
             * @custom:security-contact [email protected]
             */
            abstract contract EIP2612 is PaxosBaseAbstract {
                // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)")
                bytes32 public constant PERMIT_TYPEHASH =
                    0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
                mapping(address => uint256) internal _nonces;
                // Storage gap: https://docs.openzeppelin.com/upgrades-plugins/1.x/writing-upgradeable#storage-gaps
                uint256[10] private __gap_EIP2612; // solhint-disable-line var-name-mixedcase
                error BlockedAccountOwner();
                error PermitExpired();
                /**
                 * @notice Nonces for permit
                 * @param owner Token owner's address
                 * @return Next nonce
                 */
                function nonces(address owner) external view returns (uint256) {
                    return _nonces[owner];
                }
                /**
                 * @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 this expires (unix time)
                 * @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 whenNotPaused {
                    if (deadline < block.timestamp) revert PermitExpired();
                    if (isAddrBlocked(owner)) revert BlockedAccountOwner();
                    if (isAddrBlocked(spender)) revert BlockedAccountSpender();
                    bytes memory data = abi.encode(
                        PERMIT_TYPEHASH,
                        owner,
                        spender,
                        value,
                        _nonces[owner]++,
                        deadline
                    );
                    if (EIP712.recover(DOMAIN_SEPARATOR(), v, r, s, data) != owner)
                        revert InvalidSignature();
                    _approve(owner, spender, value);
                }
            }
            // SPDX-License-Identifier: MIT
            pragma solidity 0.8.17;
            import {PaxosBaseAbstract} from "./PaxosBaseAbstract.sol";
            import {EIP712} from "./EIP712.sol";
            /**
             * @title EIP3009 contract
             * @dev An abstract contract to provide EIP3009 functionality.
             * @notice These functions do not prevent replay attacks when an initial 
             * transaction fails. If conditions change, such as the contract going
             * from paused to unpaused, an external observer can reuse the data from the 
             * failed transaction to execute it later.
             * @custom:security-contact [email protected]
             */
            abstract contract EIP3009 is PaxosBaseAbstract {
                // 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 => state (true = used / false = unused)
                 */
                mapping(address => mapping(bytes32 => bool)) internal _authorizationStates;
                // Storage gap: https://docs.openzeppelin.com/upgrades-plugins/1.x/writing-upgradeable#storage-gaps
                uint256[10] private __gap_EIP3009; // solhint-disable-line var-name-mixedcase
                event AuthorizationUsed(address indexed authorizer, bytes32 indexed nonce);
                event AuthorizationCanceled(
                    address indexed authorizer,
                    bytes32 indexed nonce
                );
                event AuthorizationAlreadyUsed(address indexed authorizer, bytes32 indexed nonce);
                error CallerMustBePayee();
                error AuthorizationInvalid();
                error AuthorizationExpired();
                error BlockedAccountAuthorizer();
                /**
                 * @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
                ) external whenNotPaused {
                    _transferWithAuthorization(
                        TRANSFER_WITH_AUTHORIZATION_TYPEHASH,
                        from,
                        to,
                        value,
                        validAfter,
                        validBefore,
                        nonce,
                        v,
                        r,
                        s
                    );
                }
                /**
                 * @notice Execute a batched transfer with signed authorizations
                 * @param from          Array of payer addresses
                 * @param to            Array of payee addresses
                 * @param value         Array of amounts to be transferred
                 * @param validAfter    Array of times after which the transfer is valid (unix time)
                 * @param validBefore   Array of times before which the transfer is valid (unix time)
                 * @param nonce         Array of unique nonces
                 * @param v             Array of v part of the signatures
                 * @param r             Array of r part of the signatures
                 * @param s             Array of s part of the signatures
                 */
                function transferWithAuthorizationBatch(
                    address[] memory from,
                    address[] memory to,
                    uint256[] memory value,
                    uint256[] memory validAfter,
                    uint256[] memory validBefore,
                    bytes32[] memory nonce,
                    uint8[] memory v,
                    bytes32[] memory r,
                    bytes32[] memory s
                ) external whenNotPaused {
                    if (
                        !(to.length == from.length &&
                            value.length == from.length &&
                            validAfter.length == from.length &&
                            validBefore.length == from.length &&
                            nonce.length == from.length &&
                            v.length == from.length &&
                            r.length == from.length &&
                            s.length == from.length)
                    ) {
                        revert ArgumentLengthMismatch();
                    }
                    for (uint256 i = 0; i < from.length;) {
                        _transferWithAuthorization(
                            TRANSFER_WITH_AUTHORIZATION_TYPEHASH,
                            from[i],
                            to[i],
                            value[i],
                            validAfter[i],
                            validBefore[i],
                            nonce[i],
                            v[i],
                            r[i],
                            s[i]
                        );
                        unchecked { ++i; }
                    }
                }
                /**
                 * @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. (See security
                 * considerations)
                 * @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 {
                    if (to != msg.sender) revert CallerMustBePayee();
                    _transferWithAuthorization(
                        RECEIVE_WITH_AUTHORIZATION_TYPEHASH,
                        from,
                        to,
                        value,
                        validAfter,
                        validBefore,
                        nonce,
                        v,
                        r,
                        s
                    );
                }
                /**
                 * @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
                ) external whenNotPaused {
                    if (isAddrBlocked(authorizer)) revert BlockedAccountAuthorizer();
                    if (_authorizationStates[authorizer][nonce]) {
                        emit AuthorizationAlreadyUsed(authorizer, nonce);
                        return; //Return instead of throwing an error to prevent revert of a complex transaction with authorized inner transactions. Helps preventing the frontrunning tx to cause griefing
                    }
                    bytes memory data = abi.encode(
                        CANCEL_AUTHORIZATION_TYPEHASH,
                        authorizer,
                        nonce
                    );
                    if (EIP712.recover(DOMAIN_SEPARATOR(), v, r, s, data) != authorizer)
                        revert InvalidSignature();
                    _authorizationStates[authorizer][nonce] = true;
                    emit AuthorizationCanceled(authorizer, nonce);
                }
                /**
                 * @notice Internal function to execute a transfer with a signed authorization
                 * @param typeHash      Hash of the authorization type
                 * @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(
                    bytes32 typeHash,
                    address from,
                    address to,
                    uint256 value,
                    uint256 validAfter,
                    uint256 validBefore,
                    bytes32 nonce,
                    uint8 v,
                    bytes32 r,
                    bytes32 s
                ) internal {
                    if (block.timestamp <= validAfter) revert AuthorizationInvalid();
                    if (block.timestamp >= validBefore) revert AuthorizationExpired();
                    if (_authorizationStates[from][nonce]) {
                        emit AuthorizationAlreadyUsed(from, nonce);
                        return; //Return instead of throwing an error to prevent revert of a complex transaction with authorized inner transactions. Helps preventing the frontrunning tx to cause griefing
                    }
                    bytes memory data = abi.encode(
                        typeHash,
                        from,
                        to,
                        value,
                        validAfter,
                        validBefore,
                        nonce
                    );
                    if (EIP712.recover(DOMAIN_SEPARATOR(), v, r, s, data) != from)
                        revert InvalidSignature();
                    _authorizationStates[from][nonce] = true;
                    emit AuthorizationUsed(from, nonce);
                    _transfer(from, to, value);
                }
            }
            // SPDX-License-Identifier: MIT
            pragma solidity 0.8.17;
            import {ECRecover} from "./ECRecover.sol";
            /**
             * @title EIP712
             * @notice A library that provides EIP712 helper functions
             * @custom:security-contact [email protected]
             */
            library EIP712 {
                // keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)")
                bytes32 public constant EIP712_DOMAIN_TYPEHASH =
                    0x8b73c3c69bb8fe3d512ecc4cf759cc79239f7b179b0ffacaa9a75d522b39400f;
                /**
                 * @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) {
                    return
                        keccak256(
                            abi.encode(
                                EIP712_DOMAIN_TYPEHASH,
                                keccak256(bytes(name)),
                                keccak256(bytes(version)),
                                block.chainid,
                                address(this)
                            )
                        );
                }
                /**
                 * @notice Recover signer's address from a EIP712 signature
                 * @param domainSeparator   Domain separator
                 * @param v                 v of the signature
                 * @param r                 r of the signature
                 * @param s                 s of the signature
                 * @param typeHashAndData   Type hash concatenated with data
                 * @return Signer's address
                 */
                function recover(
                    bytes32 domainSeparator,
                    uint8 v,
                    bytes32 r,
                    bytes32 s,
                    bytes memory typeHashAndData
                ) internal pure returns (address) {
                    bytes32 digest = keccak256(
                        abi.encodePacked(
                            "\\x19\\x01",
                            domainSeparator,
                            keccak256(typeHashAndData)
                        )
                    );
                    return ECRecover.recover(digest, v, r, s);
                }
            }
            // SPDX-License-Identifier: MIT
            pragma solidity 0.8.17;
            import {PausableUpgradeable} from "@openzeppelin/contracts-upgradeable/security/PausableUpgradeable.sol";
            /**
             * @dev PaxosBaseAbstract
             * An abstract contract for Paxos tokens with additional internal functions.
             * @custom:security-contact [email protected]
             */
            abstract contract PaxosBaseAbstract is PausableUpgradeable {
                function _approve(
                    address owner,
                    address spender,
                    uint256 amount
                ) internal virtual;
                function _transfer(
                    address _from,
                    address _to,
                    uint256 _value
                ) internal virtual;
                function isAddrBlocked(address _addr) public view virtual returns (bool);
                function DOMAIN_SEPARATOR() public view virtual returns (bytes32);
                error ArgumentLengthMismatch();
                error BlockedAccountSpender();
                error BlockedAccountSender();
                error BlockedAccountReceiver();
                error AccountNotBlocked();
                error InvalidSignature();
            }
            // SPDX-License-Identifier: MIT
            pragma solidity 0.8.17;
            import {AccessControlDefaultAdminRulesUpgradeable} from "@openzeppelin/contracts-upgradeable/access/AccessControlDefaultAdminRulesUpgradeable.sol"; // solhint-disable-line max-line-length
            import {IERC20MetadataUpgradeable} from "@openzeppelin/contracts-upgradeable/token/ERC20/extensions/IERC20MetadataUpgradeable.sol"; // solhint-disable-line max-line-length
            import {UUPSUpgradeable} from "@openzeppelin/contracts-upgradeable/proxy/utils/UUPSUpgradeable.sol";
            import {EIP2612} from "./lib/EIP2612.sol";
            import {EIP3009} from "./lib/EIP3009.sol";
            import {EIP712} from "./lib/EIP712.sol";
            /**
             * @title YBS contract
             * @dev Yield Bearing Stablecoin is a Pausable ERC20 token where token holders are allowed to earn yield.
             * @custom:security-contact [email protected]
             */
            contract YBSV1_1 is
                IERC20MetadataUpgradeable,
                AccessControlDefaultAdminRulesUpgradeable,
                UUPSUpgradeable,
                EIP2612,
                EIP3009
            {
                // ERC20 Info
                string public name;
                string public symbol;
                uint8 public decimals;
                // REBASING
                // Total rebase shares
                uint256 public totalRebaseShares;
                // Total fixed shares
                uint256 public totalFixedShares;
                // Base value for rebaseMultiplier
                uint256 private constant _BASE = 1e18;
                // Contract rebase multipliers for rebase shares
                // multiplier effective before the increase time
                uint256 public beforeIncrMult;
                // multiplier effective after the increase time
                uint256 public afterIncrMult;
                // The time at which the multiplier changes from beforeIncrMult to afterIncrMult
                uint256 public multIncrTime;
                // The rebasing period to increment multIncrTime
                uint256 public rebasePeriod;
                // The max rate increase between beforeIncrMult -> afterIncrMult
                uint256 public maxRebaseRate;
                // Mapping of rebase shares per account
                mapping(address => uint256) private _rebaseShares;
                // Mapping of fixed shares per account
                mapping(address => uint256) private _fixedShares;
                // BLOCKLIST / FREEZE & SEIZE
                // Mapping of block/freeze status per account
                mapping(address => bool) private _blocklist;
                mapping(address => bool) private _blocklistForReceiving;
                // ERC20 Allowance
                mapping(address => mapping(address => uint256)) private _allowances;
                /**
                 * @dev This empty reserved space is put in place to allow future versions to add new
                 * variables without shifting down storage in the inheritance chain.
                 * Expected storage slots used by this contract, 50.
                 * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
                 */
                uint256[35] private __gap_YBS; // solhint-disable-line var-name-mixedcase
                // Access control roles
                /**
                 * @dev The role that controls the supply of the token.
                 * Derived from keccak256("SUPPLY_CONTROLLER_ROLE")
                 */
                bytes32 public constant SUPPLY_CONTROLLER_ROLE = 0x9c00d6f280439b1dfa4da90321e0a3f3c2e87280f4d07fea9fa43ff2cf02df2b;
                /**
                 * @dev The role that allows accounts to pause the contract.
                 * Derived from keccak256("PAUSE_ROLE")
                 */
                bytes32 public constant PAUSE_ROLE = 0x139c2898040ef16910dc9f44dc697df79363da767d8bc92f2e310312b816e46d;
                /**
                 * @dev The role that can block accounts and seize assets.
                 * Derived from keccak256("ASSET_PROTECTION_ROLE")
                 */
                bytes32 public constant ASSET_PROTECTION_ROLE = 0xe3e4f9d7569515307c0cdec302af069a93c9e33f325269bac70e6e22465a9796;
                /**
                 * @dev The role that can set rebase parameters.
                 * Derived from keccak256("REBASE_ADMIN_ROLE")
                 */
                bytes32 public constant REBASE_ADMIN_ROLE = 0x1def088e742814a6c13355302c4cd95da961f82267b7106f2e38fbc5414a570e;
                /**
                 * @dev The role that can increase the rebase multiplier.
                 * Derived from keccak256("REBASE_ROLE")
                 */
                bytes32 public constant REBASE_ROLE = 0x2cb8fee3430f011f8ea5df36a120dd5a293aa25c9ca88cc51159a94f41f768bb;
                /**
                 * @dev The wrapped YBS contract
                 * Derived from keccak256("WRAPPED_YBS_ROLE")
                 */
                bytes32 public constant WRAPPED_YBS_ROLE = 0x0d6cd32288790d7ef9cfeeb647381d8116dbc309cfa95f50cbb9e1956d87eb44;
                // Events
                event AccountBlocked(address indexed account);
                event AccountUnblocked(address indexed account);
                event AccountBlockedFromReceivingToken(address indexed account);
                event AccountUnblockedFromReceivingToken(address indexed account);
                event BlockedAccountWiped(address indexed account);
                event RebasePeriodSet(uint256 indexed value);
                event MaxRebaseRateSet(uint256 indexed value);
                event RebaseMultipliersSet(uint256 indexed beforeIncrMult_, uint256 indexed afterIncrMult_, uint256 indexed multIncrTime_);
                event SupplyIncreased(address indexed to, uint256 value);
                event SupplyDecreased(address indexed from, uint256 value);
                // ERC20 Errors from https://eips.ethereum.org/EIPS/eip-6093
                error ERC20InsufficientBalance(
                    address sender,
                    uint256 shares,
                    uint256 sharesNeeded
                );
                error ERC20InvalidSender(address sender);
                error ERC20InvalidReceiver(address receiver);
                error ERC20InsufficientAllowance(
                    address spender,
                    uint256 allowance,
                    uint256 needed
                );
                error ERC20InvalidApprover(address approver);
                error ERC20InvalidSpender(address spender);
                // YBS Errors
                error InsufficientSupply(
                    address sender,
                    uint256 shares,
                    uint256 sharesNeeded
                );
                error InvalidRebaseMultiplier(uint256 multiplier);
                error RetroactiveRebase();
                error InvalidRebaseRate(uint256 rate);
                error InvalidMaxRebaseRate(uint256 value);
                error NextIncreaseAlreadySet();
                error UnexpectedTotalSupply();
                error ZeroSharesFromValue(uint256 value);
                error ZeroAddress();
                error WYBSTransferNotAllowed();
                error CannotChangeRebaseSharesWithPendingMultiplier();
                modifier whenNoPendingMultiplier() {
                    if (block.timestamp < multIncrTime && beforeIncrMult != afterIncrMult) revert CannotChangeRebaseSharesWithPendingMultiplier();
                    _;
                }
                /// @custom:oz-upgrades-unsafe-allow constructor
                constructor() {
                    _disableInitializers();
                }
                /**
                 * @notice Initializes the contract
                 * @dev Called on deployment, only can be called once.
                 * @param name_ the token name
                 * @param symbol_ the token symbol
                 * @param decimals_ the token decimals
                 * @param admin address of the default admin
                 * @param supplyController address of the supply controller
                 * @param pauser address of the pauser
                 * @param assetProtector address of the asset protector
                 * @param rebaserAdmin address of the rebaser-admin
                 * @param rebaser address of the rebaser
                 */
                function initialize(
                    string memory name_,
                    string memory symbol_,
                    uint8 decimals_,
                    address admin,
                    address supplyController,
                    address pauser,
                    address assetProtector,
                    address rebaserAdmin,
                    address rebaser
                ) external initializer {
                    if (supplyController == address(0) || pauser == address(0) || assetProtector == address(0) || 
                        rebaserAdmin == address(0) || rebaser == address(0)) {
                        revert ZeroAddress();
                    } 
                    name = name_;
                    symbol = symbol_;
                    decimals = decimals_;
                    beforeIncrMult = _BASE;
                    afterIncrMult = _BASE;
                    multIncrTime = 0;
                    _setRebasePeriod(0);
                    _setMaxRebaseRate(0);
                    __AccessControlDefaultAdminRules_init(3 hours, admin);
                    __Pausable_init();
                    __UUPSUpgradeable_init();
                    _grantRole(SUPPLY_CONTROLLER_ROLE, supplyController);
                    _grantRole(PAUSE_ROLE, pauser);
                    _grantRole(ASSET_PROTECTION_ROLE, assetProtector);
                    _grantRole(REBASE_ADMIN_ROLE, rebaserAdmin);
                    _grantRole(REBASE_ROLE, rebaser);
                }
                /**
                 * @notice Pauses transfers.
                 * @dev Restricted to PAUSE_ROLE.
                 * @dev Inherits the _pause function from @openzeppelin/PausableUpgradeable contract.
                 */
                function pause() external onlyRole(PAUSE_ROLE) {
                    _pause();
                }
                /**
                 * @notice Unpauses transfers.
                 * @dev Restricted to PAUSE_ROLE.
                 * @dev Inherits the _unpause function from @openzeppelin/PausableUpgradeable contract.
                 */
                function unpause() external onlyRole(PAUSE_ROLE) {
                    _unpause();
                }
                /**
                 * @notice Batch block accounts.
                 * @dev Restricted to ASSET_PROTECTION_ROLE.
                 * This function intentionally does not include the whenNoPendingMultiplier() modifier
                 * since blocking accounts is a critical operation and should not be delayed.
                 * As a result, the overall payout amount would be less than originally expected
                 * for a pending multiplier since the blocked accounts would not receive the payout.
                 * @param addresses list of addresses to block.
                 */
                function blockAccounts(
                    address[] calldata addresses
                ) external onlyRole(ASSET_PROTECTION_ROLE) {
                    for (uint256 i = 0; i < addresses.length;) {
                        _blockAccount(addresses[i]);
                        unchecked { ++i; }
                    }
                }
                /**
                 * @notice Blocks multiple accounts at once from receiving funds.
                 * @dev Restricted to ASSET_PROTECTION_ROLE.
                 * @param addresses An array of addresses to be blocked.
                 */
                function blockAccountsFromReceiving(
                    address[] calldata addresses
                ) external onlyRole(ASSET_PROTECTION_ROLE) {
                    for (uint256 i = 0; i < addresses.length; ) {
                        _blocklistForReceiving[addresses[i]] = true;
                        emit AccountBlockedFromReceivingToken(addresses[i]);
                        unchecked { ++i; }
                    }
                }
                /**
                 * @notice Batch unblock accounts.
                 * @dev Restricted to ASSET_PROTECTION_ROLE.
                 * @param addresses list of addresses to unblock.
                 */
                function unblockAccounts(
                    address[] calldata addresses
                ) external onlyRole(ASSET_PROTECTION_ROLE) whenNoPendingMultiplier() {
                    for (uint256 i = 0; i < addresses.length;) {
                        _unblockAccount(addresses[i]);
                        unchecked { ++i; }
                    }
                }
                /**
                 * @notice Removes multiple accounts from the receiving blocklist at once.
                 * @dev Restricted to ASSET_PROTECTION_ROLE.
                 * @param addresses An array of addresses to be removed from the receiving blocklist.
                 */
                function unblockAccountsFromReceiving(
                    address[] calldata addresses
                ) external onlyRole(ASSET_PROTECTION_ROLE) {
                    for (uint256 i = 0; i < addresses.length;) {
                        delete _blocklistForReceiving[addresses[i]];
                        emit AccountUnblockedFromReceivingToken(addresses[i]);
                        unchecked { ++i; }
                    }
                }
                /**
                 * @notice Sets the rebase period.
                 * @dev Restricted to REBASE_ADMIN_ROLE.
                 * @param rebasePeriod_ the new rebase period.
                 */
                function setRebasePeriod(
                    uint256 rebasePeriod_
                ) external onlyRole(REBASE_ADMIN_ROLE) {
                    _setRebasePeriod(rebasePeriod_);
                }
                /**
                 * @notice Sets the max rebase rate.
                 * @dev Restricted to REBASE_ADMIN_ROLE.
                 * @param maxRebaseRate_ The new max rebase rate.
                 */
                function setMaxRebaseRate(
                    uint256 maxRebaseRate_
                ) external onlyRole(REBASE_ADMIN_ROLE) {
                    _setMaxRebaseRate(maxRebaseRate_);
                }
                /**
                 * @notice Sets the next rebase multiplier and increase time.
                 * @dev Restricted to REBASE_ADMIN_ROLE.
                 * Used in the following scenarios:
                 * 1. corrective actions when a pending increase is set, i.e. multIncrTime is in future.
                 *     a. The beforeIncrMult should be active in this case and should not change.
                 * 2. explicitly setting the next multiplier & increase time.
                 *     a. The afterIncrMult should be active in this case and roll to beforeIncrMult.
                 * @param afterIncrMult_ the contract rebase multiplier after increase
                 * @param multIncrTime_ the multiplier increase time
                 * @param expectedTotalSupply the expected total supply after the increase based on afterIncrMult_.
                 */
                function setNextMultiplier(
                    uint256 afterIncrMult_,
                    uint256 multIncrTime_,
                    uint256 expectedTotalSupply
                ) external onlyRole(REBASE_ADMIN_ROLE) {
                    // Do not allow multIncrTime_ to be in the past.
                    // If desired to only increase the multIncrTime use increaseRebaseMultiplier() with a zero rebaseRate.
                    if (multIncrTime_ < block.timestamp) {
                        revert RetroactiveRebase();
                    }
                    uint256 activeMult = _getActiveMultiplier();
                    if (afterIncrMult_ < activeMult) {
                        revert InvalidRebaseMultiplier(afterIncrMult_);
                    }
                    uint256 rebaseRate = (afterIncrMult_ - activeMult) * _BASE / activeMult;
                    if (rebaseRate > maxRebaseRate) {
                        revert InvalidRebaseRate(rebaseRate);
                    }
                    _setRebaseMultipliers(activeMult, afterIncrMult_, multIncrTime_, expectedTotalSupply);
                }
                /**
                 * @notice Increases the next multiplier and sets the increase time.
                 * @dev Restricted to REBASE_ROLE.
                 * @param rebaseRate the increase rate for the next multiplier
                 * @param expectedTotalSupply the expected total supply after the rebaseRate is applied.
                 */
                function increaseRebaseMultiplier(
                    uint256 rebaseRate,
                    uint256 expectedTotalSupply
                ) external onlyRole(REBASE_ROLE) {
                    // Revert if already been set, corrective actions should use setNextMultiplier()
                    if (multIncrTime > block.timestamp) {
                        revert NextIncreaseAlreadySet();
                    }
                    
                    if (rebaseRate > maxRebaseRate) {
                        revert InvalidRebaseRate(rebaseRate);
                    }
                    // The multIncrTime_ can be in the past only if the multiplier does not change, i.e. rebaseRate == 0. 
                    // This is needed for Operations to rely on the safer function increaseRebaseMultiplier(),
                    // in case the multiplier was not updated for longer than 'rebasePeriod' time.
                    uint256 multIncrTime_ = multIncrTime + rebasePeriod;
                    if (multIncrTime_ < block.timestamp && rebaseRate != 0) {
                        revert RetroactiveRebase();
                    }
                    uint256 afterIncrMult_ = (afterIncrMult * (_BASE + rebaseRate)) / _BASE;
                    _setRebaseMultipliers(afterIncrMult, afterIncrMult_, multIncrTime_, expectedTotalSupply);
                }
                /**
                 * @notice Returns the active rebase multiplier
                 * @return An uint256 representing the multiplier
                 */
                function getActiveMultiplier() external view returns (uint256) {
                    return _getActiveMultiplier();
                }
                /**
                 * @notice Returns the total supply
                 * @dev Converts rebase and fixed shares to tokens.
                 * @return An uint256 representing the total supply
                 */
                function totalSupply() external view returns (uint256) {
                    return
                        _convertRebaseSharesToTokens(totalRebaseShares) + totalFixedShares;
                }
                /**
                 * @notice Gets the balance of the specified account.
                 * @dev Converts an account's rebase and fixed shares to tokens.
                 * @param account account to get the balance for.
                 * @return An uint256 representing the amount owned by the passed account.
                 */
                function balanceOf(address account) external view returns (uint256) {
                    return
                        _convertRebaseSharesToTokens(_rebaseShares[account]) +
                        _fixedShares[account];
                }
                /**
                 * @dev Returns rebase shares of an account.
                 * @param account account to get the shares for.
                 * @return An uint256 representing shares.
                 */
                function rebaseSharesOf(address account) external view returns (uint256) {
                    return _rebaseShares[account];
                }
                /**
                 * @dev Returns fixed shares of an account.
                 * @param account account to get the shares for.
                 * @return An uint256 representing shares.
                 */
                function fixedSharesOf(address account) external view returns (uint256) {
                    return _fixedShares[account];
                }
                /**
                 * @dev Function to check whether the address is currently blocked.
                 * @param addr The address to check if blocked.
                 * @return A bool representing whether the given address is blocked.
                 */
                function isAddrBlocked(address addr) public view override returns (bool) {
                    return _blocklist[addr];
                }
                /**
                 * @dev Function to check whether the address is currently blocked for receiving.
                 * @param addr The address to check if blocked for receiving.
                 * @return A bool representing whether the given address is blocked for receiving.
                 */
                function isAddrBlockedForReceiving(address addr) public view returns (bool) {
                    return _blocklistForReceiving[addr];
                }
                /**
                 * Get domain Separator.
                 */
                // solhint-disable-next-line func-name-mixedcase
                function DOMAIN_SEPARATOR() public view override returns (bytes32) {
                    return EIP712.makeDomainSeparator(name, "1");
                }
                /**
                 * @notice Increases the total supply by minting the specified number of tokens to the supply controller account.
                 * @dev Converts to underlying rebase shares and checks if results in overflow for total supply.
                 * Restricted to SUPPLY_CONTROLLER_ROLE.
                 * @param value The number of tokens to add.
                 * @return success A boolean that indicates if the operation was successful.
                 */
                function increaseSupply(
                    uint256 value
                ) public onlyRole(SUPPLY_CONTROLLER_ROLE) whenNoPendingMultiplier() returns (bool success) {
                    // Do not allow blocked address to get rebaseShares. This check is only necessary for increaseSupply,
                    // as decreaseSupply will revert due to insufficient rebaseShares.
                    if (_blocklist[msg.sender]) revert BlockedAccountSender();
                    uint256 shares = _convertToRebaseShares(value);
                    if (shares == 0) revert ZeroSharesFromValue(value);
                    totalRebaseShares += shares;
                    // overflow check - attempt to convert back to total supply,
                    // This should revert if large amount results in overflow of total supply
                    _convertRebaseSharesToTokens(totalRebaseShares) + totalFixedShares;
                    unchecked {
                        _rebaseShares[msg.sender] += shares;
                    }
                    emit SupplyIncreased(msg.sender, value);
                    emit Transfer(address(0), msg.sender, value);
                    return true;
                }
                /**
                 * @notice Decreases the total supply by burning the specified number of tokens from the supply controller account.
                 * @dev Converts to underlying rebase shares. Restricted to SUPPLY_CONTROLLER_ROLE.
                 * @param value The number of tokens to remove.
                 * @return success A boolean that indicates if the operation was successful.
                 */
                function decreaseSupply(
                    uint256 value
                ) public onlyRole(SUPPLY_CONTROLLER_ROLE) whenNoPendingMultiplier() returns (bool success) {
                    uint256 shares = _convertToRebaseShares(value);
                    if (shares == 0) revert ZeroSharesFromValue(value);
                    uint256 hasShares = _rebaseShares[msg.sender];
                    if (shares > hasShares)
                        revert InsufficientSupply(msg.sender, hasShares, shares);
                    unchecked {
                        // Cannot underflow, shares must be less than or equal to hasShares to get here
                        _rebaseShares[msg.sender] -= shares;
                        // Cannot underflow, totalRebaseShares is always greater than or equal to account shares 
                        totalRebaseShares -= shares;
                    }
                    emit SupplyDecreased(msg.sender, value);
                    emit Transfer(msg.sender, address(0), value);
                    return true;
                }
                /**
                 * @notice Transfer token to a specified address from msg.sender
                 * @param to The address to transfer to.
                 * @param amount The amount to be transferred.
                 * @return True when the operation was successful.
                 */
                function transfer(
                    address to,
                    uint256 amount
                ) public whenNotPaused returns (bool) {
                    _transfer(msg.sender, to, amount);
                    return true;
                }
                /**
                 * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
                 * 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
                 * 
                 * Recommended to use increaseApproval and decreaseApproval instead
                 * 
                 * @param spender The address which will spend the funds.
                 * @param amount The amount of tokens to be spent.
                 * @return True when the operation was successful.
                 */
                function approve(
                    address spender,
                    uint256 amount
                ) public whenNotPaused returns (bool) {
                    _approve(msg.sender, spender, amount);
                    return true;
                }
                /**
                 * @notice Function to check the amount of tokens that an owner allowed to a spender.
                 * @dev Allowances are represented in tokens rather than rebase shares.
                 * @param owner The address which owns the funds.
                 * @param spender The address which will spend the funds.
                 * @return A uint256 specifying the amount of tokens still available for the spender.
                 */
                function allowance(
                    address owner,
                    address spender
                ) public view returns (uint256) {
                    return _allowances[owner][spender];
                }
                /**
                 * @dev Increase the amount of tokens that an owner allowed to a spender.
                 *
                 * To increment allowed value is better to use this function to avoid 2 calls (and wait until the first transaction
                 * is mined) instead of approve.
                 * @param spender The address which will spend the funds.
                 * @param addedValue The amount of tokens to increase the allowance by.
                 * @return True when the operation was successful.
                 */
                function increaseApproval(
                    address spender,
                    uint256 addedValue
                ) public whenNotPaused returns (bool) {
                    _beforeApprove(spender);
                    _allowances[msg.sender][spender] += addedValue;
                    emit Approval(msg.sender, spender, _allowances[msg.sender][spender]);
                    return true;
                }
                /**
                 * @dev Decrease the amount of tokens that an owner allowed to a spender.
                 *
                 * To decrement allowed value is better to use this function to avoid 2 calls
                 * (and wait until the first transaction is mined) instead of approve.
                 * @param spender The address which will spend the funds.
                 * @param subtractedValue The amount of tokens to decrease the allowance by.
                 * @return True when the operation was successful.
                 */
                function decreaseApproval(
                    address spender,
                    uint256 subtractedValue
                ) public whenNotPaused returns (bool) {
                    _beforeApprove(spender);
                    uint256 oldValue = _allowances[msg.sender][spender];
                    if (subtractedValue > oldValue) {
                        delete _allowances[msg.sender][spender];
                    } else {
                        unchecked {
                            _allowances[msg.sender][spender] -= subtractedValue;
                        }
                    }
                    emit Approval(msg.sender, spender, _allowances[msg.sender][spender]);
                    return true;
                }
                /**
                 * @dev Transfer tokens from one address to another
                 * @param from The address which you want to send tokens from
                 * @param to The address which you want to transfer to
                 * @param amount the amount of tokens to be transferred
                 * @return True when the operation was successful.
                 */
                function transferFrom(
                    address from,
                    address to,
                    uint256 amount
                ) public whenNotPaused returns (bool) {
                    if (_blocklist[msg.sender]) revert BlockedAccountSpender();
                    _transferFromAllowance(from, to, amount);
                    return true;
                }
                /**
                 * @dev Transfer tokens from one set of addresses to another set in a single transaction.
                 * @param from The addresses which you want to send tokens from
                 * @param to The addresses which you want to transfer to
                 * @param value The amounts of tokens to be transferred
                 * @return True if successful
                 */
                function transferFromBatch(
                    address[] calldata from,
                    address[] calldata to,
                    uint256[] calldata value
                ) public whenNotPaused returns (bool)
                {
                    if (!(to.length == from.length && value.length == from.length)) revert ArgumentLengthMismatch();
                    if (_blocklist[msg.sender]) revert BlockedAccountSpender();
                    for (uint256 i = 0; i < from.length;) {
                        _transferFromAllowance(from[i], to[i], value[i]);
                        unchecked { ++i; }
                    }
                    return true;
                }
                /**
                 * @dev Wipes the balance of a blocked address, and burns the tokens.
                 * Restricted to ASSET_PROTECTION_ROLE.
                 * @param addr The blocked address to wipe.
                 */
                function wipeBlockedAddress(
                    address addr
                ) public onlyRole(ASSET_PROTECTION_ROLE) {
                    if (!_blocklist[addr]) revert AccountNotBlocked();
                    uint256 fixedShares = _fixedShares[addr];
                    delete _fixedShares[addr];
                    unchecked {
                        totalFixedShares -= fixedShares;
                    }
                    emit BlockedAccountWiped(addr);
                    emit SupplyDecreased(addr, fixedShares);
                    emit Transfer(addr, address(0), fixedShares);
                }
                /**
                 * @dev Internal function to transfer tokens
                 * @param from The address to transfer from.
                 * @param to The address to transfer to.
                 * @param amount The amount to be transferred.
                 */
                function _transfer(address from, address to, uint256 amount) internal override {
                    if (from == address(0)) revert ERC20InvalidSender(from);
                    if (to == address(0)) revert ERC20InvalidReceiver(to);
                    if (_blocklist[from]) revert BlockedAccountSender();
                    if (_blocklist[to]) revert BlockedAccountReceiver();
                    if (_blocklistForReceiving[to]) revert BlockedAccountReceiver();
                    
                    // To prevent inflation attacks on the wYBS contract, block direct transfers.
                    if (hasRole(WRAPPED_YBS_ROLE, to) && (!hasRole(WRAPPED_YBS_ROLE, msg.sender) || hasRole(WRAPPED_YBS_ROLE, from))) revert WYBSTransferNotAllowed();
                    uint256 shares = _convertToRebaseShares(amount);
                    if (shares == 0) revert ZeroSharesFromValue(amount);
                    uint256 fromShares = _rebaseShares[from];
                    if (shares > fromShares)
                        revert ERC20InsufficientBalance(from, fromShares, shares);
                    unchecked {
                        _rebaseShares[from] -= shares;
                        _rebaseShares[to] += shares;
                    }
                    emit Transfer(from, to, amount);
                }
                /**
                 * @dev Internal function to set the rebase period.
                 * @param rebasePeriod_ The new rebase period.
                 */
                function _setRebasePeriod(uint256 rebasePeriod_) internal {
                    rebasePeriod = rebasePeriod_;
                    emit RebasePeriodSet(rebasePeriod_);
                }
                /**
                 * @dev Internal function to set the max rebase rate.
                 * @param maxRebaseRate_ The new max rebase rate.
                 */
                function _setMaxRebaseRate(uint256 maxRebaseRate_) internal {
                    if (maxRebaseRate_ > _BASE) {
                        revert InvalidMaxRebaseRate(maxRebaseRate_);
                    }
                    maxRebaseRate = maxRebaseRate_;
                    emit MaxRebaseRateSet(maxRebaseRate_);
                }
                /**
                 * @dev Internal function to set the rebase multipliers and increase time.
                 * Note: this function assumes after mult is greater than or equal to before mult.
                 * @param beforeIncrMult_ The new rebase multiplier before increase.
                 * @param afterIncrMult_ The new rebase multiplier after increase.
                 * @param multIncrTime_ The rebase multiplier increase time.
                 * @param expectedTotalSupply The expected total supply after the increase based on afterIncrMult_.
                 */
                function _setRebaseMultipliers(uint256 beforeIncrMult_,
                                               uint256 afterIncrMult_,
                                               uint256 multIncrTime_,
                                               uint256 expectedTotalSupply) internal {
                    if ((totalRebaseShares * afterIncrMult_ / _BASE ) + totalFixedShares > expectedTotalSupply) {
                        revert UnexpectedTotalSupply();
                    }
                    beforeIncrMult = beforeIncrMult_;
                    afterIncrMult = afterIncrMult_;
                    multIncrTime = multIncrTime_;
                    emit RebaseMultipliersSet(beforeIncrMult_, afterIncrMult_, multIncrTime_);
                }
                /**
                 * @dev required by the OZ UUPS module to authorize an upgrade 
                 * of the contract. Restricted to DEFAULT_ADMIN_ROLE.
                 */
                function _authorizeUpgrade(
                    address
                ) internal override onlyRole(DEFAULT_ADMIN_ROLE) {} // solhint-disable-line no-empty-blocks
                /**
                 * @dev Private helper function used by approve and increase/decreaseApproval
                 * @param spender The address which will spend the funds.
                 */
                function _beforeApprove(address spender) private view {
                    if (msg.sender == address(0)) revert ERC20InvalidApprover(msg.sender);
                    if (spender == address(0)) revert ERC20InvalidSpender(spender);
                    if (_blocklist[spender]) revert BlockedAccountSpender();
                    if (_blocklist[msg.sender]) revert BlockedAccountSender();
                }
                /**
                 * @dev Private function to add an account to the _blocklist.
                 * The token holder's rebase shares are converted to fixed shares.
                 * @param account The account to block.
                 */
                function _blockAccount(address account) private {
                    _convertRebaseSharesToFixedShares(account);
                    _blocklist[account] = true;
                    emit AccountBlocked(account);
                }
                /**
                 * @dev Private function to remove an account from the _blocklist.
                 * The token holder's fixed shares are converted back to rebase shares.
                 * @param account The account to unblock.
                 */
                function _unblockAccount(address account) private {
                    _convertFixedSharesToRebaseShares(account);
                    delete _blocklist[account];
                    emit AccountUnblocked(account);
                }
                /**
                 * @dev Private function that converts rebase shares to fixed shares.
                 * @param account The account whose shares will be converted
                 */
                function _convertRebaseSharesToFixedShares(address account) private {
                    if (_rebaseShares[account] == 0) return;
                    uint256 shares = _rebaseShares[account];
                    uint256 amount = _convertRebaseSharesToTokens(shares);
                    delete _rebaseShares[account];
                    unchecked{
                        totalRebaseShares -= shares;
                    }
                    _fixedShares[account] += amount;
                    totalFixedShares += amount;
                }
                /**
                 * @dev Private function that converts fixed shares to rebase shares.
                 * @param account The account whose shares will be converted
                 */
                function _convertFixedSharesToRebaseShares(address account) private {
                    if (_fixedShares[account] == 0) return;
                    uint256 amount = _fixedShares[account];
                    uint256 shares = _convertToRebaseShares(amount);
                    if (shares == 0) revert ZeroSharesFromValue(amount);
                    delete _fixedShares[account];
                    unchecked {
                        totalFixedShares -= amount;
                    }
                    _rebaseShares[account] += shares;
                    totalRebaseShares += shares;
                }
                /**
                 * @dev Private function that returns the active rebase multiplier
                 * @return An uint256 representing the multiplier
                 */
                function _getActiveMultiplier() private view returns (uint256) {
                    if (block.timestamp >= multIncrTime) {
                        return afterIncrMult;
                    }
                    
                    return beforeIncrMult;
                }
                /**
                 * @dev Private function that converts rebase shares to tokens.
                 * @param shares The shares to be converted.
                 * @return An uint256 representing tokens.
                 */
                function _convertRebaseSharesToTokens(
                    uint256 shares
                ) private view returns (uint256) {
                    return (shares * _getActiveMultiplier()) / _BASE;
                }
                /**
                 * @dev Private function that converts tokens to rebase shares.
                 * @param amount The amount to be converted.
                 * @return An uint256 representing shares.
                 */
                function _convertToRebaseShares(
                    uint256 amount
                ) private view returns (uint256) {
                    return (amount * _BASE) / _getActiveMultiplier();
                }
                /**
                 * @dev Set allowance for a given spender, of a given owner.
                 * @param owner The address which owns the funds.
                 * @param spender The address which will spend the funds.
                 * @param value The amount of tokens to be approved.
                 */
                function _approve(
                    address owner,
                    address spender,
                    uint256 value
                ) internal override {
                    _beforeApprove(spender);
                    _allowances[owner][spender] = value;
                    emit Approval(owner, spender, value);
                }
                /**
                 * @dev Internal function to transfer balances from => to.
                 * Internal to the contract - see transferFrom and transferFromBatch.
                 * @param from The address which you want to send tokens from
                 * @param to The address which you want to transfer to
                 * @param value the amount of tokens to be transferred
                 */
                function _transferFromAllowance(
                    address from,
                    address to,
                    uint256 value
                )
                internal
                {
                    uint256 currentAllowance = _allowances[from][msg.sender];
                    if (currentAllowance != type(uint256).max) {
                        if (value > currentAllowance)
                            revert ERC20InsufficientAllowance(
                                msg.sender,
                                currentAllowance,
                                value
                            );
                        unchecked {
                            _allowances[from][msg.sender] -= value;
                        }
                    }
                    _transfer(from, to, value);
                }
            }