// File: contracts/proxy/upgradeable/FMB_Proxy.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import { UpgradeableProxyOwnable } from "./UpgradeableProxyOwnable.sol";

contract ReleaseProxy is UpgradeableProxyOwnable {
    address public FMB;
    uint256 public CLIFF;
    uint256 public PERIOD;
    uint256 public RELEASE;
    uint256 public tokenInitTS;
    uint256 public lastReleasedTS;
    address public beneficiary; 
    

    constructor() {
        _setOwner(msg.sender);
    }


    /**
     * @dev suppress compiler warning
     */
    receive() external payable {}
}
// File: contracts/proxy/upgradeable/UpgradeableProxyOwnable.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

import { OwnableInternal } from '../../access/ownable/OwnableInternal.sol';
import { IUpgradeableProxyOwnable } from './IUpgradeableProxyOwnable.sol';
import { UpgradeableProxy } from './UpgradeableProxy.sol';

/**
 * @title Proxy with upgradeable implementation controlled by ERC171 owner
 */
abstract contract UpgradeableProxyOwnable is
    IUpgradeableProxyOwnable,
    UpgradeableProxy,
    OwnableInternal
{
    /**
     * @notice set logic implementation address
     * @param implementation implementation address
     */
    function setImplementation(address implementation) external onlyOwner {
        _setImplementation(implementation);
    }
}

// File: @openzeppelin/contracts/token/ERC20/ERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/ERC20.sol)

pragma solidity ^0.8.0;

import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/Context.sol";

/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * The default value of {decimals} is 18. To change this, you should override
 * this function so it returns a different value.
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC20
 * applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;

    mapping(address => mapping(address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the default value returned by this function, unless
     * it's overridden.
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual override returns (uint8) {
        return 18;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address to, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
     * `transferFrom`. This is semantically equivalent to an infinite approval.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * NOTE: Does not update the allowance if the current allowance
     * is the maximum `uint256`.
     *
     * Requirements:
     *
     * - `from` and `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `amount`.
     */
    function transferFrom(address from, address to, uint256 amount) public virtual override returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, amount);
        _transfer(from, to, amount);
        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, allowance(owner, spender) + addedValue);
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        address owner = _msgSender();
        uint256 currentAllowance = allowance(owner, spender);
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(owner, spender, currentAllowance - subtractedValue);
        }

        return true;
    }

    /**
     * @dev Moves `amount` of tokens from `from` to `to`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     */
    function _transfer(address from, address to, uint256 amount) internal virtual {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(from, to, amount);

        uint256 fromBalance = _balances[from];
        require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[from] = fromBalance - amount;
            // Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
            // decrementing then incrementing.
            _balances[to] += amount;
        }

        emit Transfer(from, to, amount);

        _afterTokenTransfer(from, to, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply += amount;
        unchecked {
            // Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
            _balances[account] += amount;
        }
        emit Transfer(address(0), account, amount);

        _afterTokenTransfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
            // Overflow not possible: amount <= accountBalance <= totalSupply.
            _totalSupply -= amount;
        }

        emit Transfer(account, address(0), amount);

        _afterTokenTransfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(address owner, address spender, uint256 amount) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Updates `owner` s allowance for `spender` based on spent `amount`.
     *
     * Does not update the allowance amount in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Might emit an {Approval} event.
     */
    function _spendAllowance(address owner, address spender, uint256 amount) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance != type(uint256).max) {
            require(currentAllowance >= amount, "ERC20: insufficient allowance");
            unchecked {
                _approve(owner, spender, currentAllowance - amount);
            }
        }
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual {}

    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * has been transferred to `to`.
     * - when `from` is zero, `amount` tokens have been minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(address from, address to, uint256 amount) internal virtual {}
}

// File: contracts/proxy/upgradeable/UpgradeableProxy.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

import { Proxy } from '../Proxy.sol';
import { IUpgradeableProxy } from './IUpgradeableProxy.sol';
import { UpgradeableProxyStorage } from './UpgradeableProxyStorage.sol';

/**
 * @title Proxy with upgradeable implementation
 */
abstract contract UpgradeableProxy is IUpgradeableProxy, Proxy {
    /**
     * @inheritdoc Proxy
     */
    function _getImplementation() internal view override returns (address) {
        // inline storage layout retrieval uses less gas
        UpgradeableProxyStorage.Layout storage l;
        bytes32 slot = UpgradeableProxyStorage.STORAGE_SLOT;
        assembly {
            l.slot := slot
        }

        return l.implementation;
    }

    /**
     * @notice set logic implementation address
     * @param implementation implementation address
     */
    function _setImplementation(address implementation) internal {
        UpgradeableProxyStorage.layout().implementation = implementation;
    }
}

// File: contracts/proxy/upgradeable/IUpgradeableProxyOwnable.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

import { IUpgradeableProxy } from './IUpgradeableProxy.sol';

interface IUpgradeableProxyOwnable is IUpgradeableProxy {
    /**
     * TODO: add to IUpgradeableProxy or remove from here
     */
    function setImplementation(address implementation) external;
}

// File: contracts/access/ownable/OwnableInternal.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

import { IERC173 } from '../../interfaces/IERC173.sol';
import { AddressUtils } from '../../utils/AddressUtils.sol';
import { IOwnableInternal } from './IOwnableInternal.sol';
import { OwnableStorage } from './OwnableStorage.sol';

abstract contract OwnableInternal is IOwnableInternal {
    using AddressUtils for address;

    modifier onlyOwner() {
        if (msg.sender != _owner()) revert Ownable__NotOwner();
        _;
    }

    modifier onlyTransitiveOwner() {
        if (msg.sender != _transitiveOwner())
            revert Ownable__NotTransitiveOwner();
        _;
    }

    function _owner() internal view virtual returns (address) {
        return OwnableStorage.layout().owner;
    }

    function _transitiveOwner() internal view virtual returns (address owner) {
        owner = _owner();

        while (owner.isContract()) {
            try IERC173(owner).owner() returns (address transitiveOwner) {
                owner = transitiveOwner;
            } catch {
                break;
            }
        }
    }

    function _transferOwnership(address account) internal virtual {
        _setOwner(account);
    }

    function _setOwner(address account) internal virtual {
        OwnableStorage.Layout storage l = OwnableStorage.layout();
        emit OwnershipTransferred(l.owner, account);
        l.owner = account;
    }
}

// File: @openzeppelin/contracts/utils/Context.sol



// 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;
    }
}

// File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);

    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address from, address to, uint256 amount) external returns (bool);
}

// File: contracts/proxy/upgradeable/UpgradeableProxyStorage.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

library UpgradeableProxyStorage {
    struct Layout {
        address implementation;
    }

    bytes32 internal constant STORAGE_SLOT =
        keccak256('solidstate.contracts.storage.UpgradeableProxy');

    function layout() internal pure returns (Layout storage l) {
        bytes32 slot = STORAGE_SLOT;
        assembly {
            l.slot := slot
        }
    }
}

// File: contracts/proxy/upgradeable/IUpgradeableProxy.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

import { IProxy } from '../IProxy.sol';

interface IUpgradeableProxy is IProxy {}

// File: contracts/proxy/Proxy.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

import { AddressUtils } from '../utils/AddressUtils.sol';
import { IProxy } from './IProxy.sol';

/**
 * @title Base proxy contract
 */
abstract contract Proxy is IProxy {
    using AddressUtils for address;

    /**
     * @notice delegate all calls to implementation contract
     * @dev reverts if implementation address contains no code, for compatibility with metamorphic contracts
     * @dev memory location in use by assembly may be unsafe in other contexts
     */
    fallback() external payable virtual {
        address implementation = _getImplementation();

        if (!implementation.isContract())
            revert Proxy__ImplementationIsNotContract();

        assembly {
            calldatacopy(0, 0, calldatasize())
            let result := delegatecall(
                gas(),
                implementation,
                0,
                calldatasize(),
                0,
                0
            )
            returndatacopy(0, 0, returndatasize())

            switch result
            case 0 {
                revert(0, returndatasize())
            }
            default {
                return(0, returndatasize())
            }
        }
    }

    /**
     * @notice get logic implementation address
     * @return implementation address
     */
    function _getImplementation() internal virtual returns (address);
}

// File: contracts/access/ownable/OwnableStorage.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

library OwnableStorage {
    struct Layout {
        address owner;
    }

    bytes32 internal constant STORAGE_SLOT =
        keccak256('solidstate.contracts.storage.Ownable');

    function layout() internal pure returns (Layout storage l) {
        bytes32 slot = STORAGE_SLOT;
        assembly {
            l.slot := slot
        }
    }
}

// File: contracts/access/ownable/IOwnableInternal.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

import { IERC173Internal } from '../../interfaces/IERC173Internal.sol';

interface IOwnableInternal is IERC173Internal {
    error Ownable__NotOwner();
    error Ownable__NotTransitiveOwner();
}

// File: contracts/utils/AddressUtils.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

import { UintUtils } from './UintUtils.sol';

library AddressUtils {
    using UintUtils for uint256;

    error AddressUtils__InsufficientBalance();
    error AddressUtils__NotContract();
    error AddressUtils__SendValueFailed();

    function toString(address account) internal pure returns (string memory) {
        return uint256(uint160(account)).toHexString(20);
    }

    function isContract(address account) internal view returns (bool) {
        uint256 size;
        assembly {
            size := extcodesize(account)
        }
        return size > 0;
    }

    function sendValue(address payable account, uint256 amount) internal {
        (bool success, ) = account.call{ value: amount }('');
        if (!success) revert AddressUtils__SendValueFailed();
    }

    function functionCall(
        address target,
        bytes memory data
    ) internal returns (bytes memory) {
        return
            functionCall(target, data, 'AddressUtils: failed low-level call');
    }

    function functionCall(
        address target,
        bytes memory data,
        string memory error
    ) internal returns (bytes memory) {
        return _functionCallWithValue(target, data, 0, error);
    }

    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return
            functionCallWithValue(
                target,
                data,
                value,
                'AddressUtils: failed low-level call with value'
            );
    }

    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory error
    ) internal returns (bytes memory) {
        if (value > address(this).balance)
            revert AddressUtils__InsufficientBalance();
        return _functionCallWithValue(target, data, value, error);
    }

    /**
     * @notice execute arbitrary external call with limited gas usage and amount of copied return data
     * @dev derived from https://github.com/nomad-xyz/ExcessivelySafeCall (MIT License)
     * @param target recipient of call
     * @param gasAmount gas allowance for call
     * @param value native token value to include in call
     * @param maxCopy maximum number of bytes to copy from return data
     * @param data encoded call data
     * @return success whether call is successful
     * @return returnData copied return data
     */
    function excessivelySafeCall(
        address target,
        uint256 gasAmount,
        uint256 value,
        uint16 maxCopy,
        bytes memory data
    ) internal returns (bool success, bytes memory returnData) {
        returnData = new bytes(maxCopy);

        assembly {
            // execute external call via assembly to avoid automatic copying of return data
            success := call(
                gasAmount,
                target,
                value,
                add(data, 0x20),
                mload(data),
                0,
                0
            )

            // determine whether to limit amount of data to copy
            let toCopy := returndatasize()

            if gt(toCopy, maxCopy) {
                toCopy := maxCopy
            }

            // store the length of the copied bytes
            mstore(returnData, toCopy)

            // copy the bytes from returndata[0:toCopy]
            returndatacopy(add(returnData, 0x20), 0, toCopy)
        }
    }

    function _functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory error
    ) private returns (bytes memory) {
        if (!isContract(target)) revert AddressUtils__NotContract();

        (bool success, bytes memory returnData) = target.call{ value: value }(
            data
        );

        if (success) {
            return returnData;
        } else if (returnData.length > 0) {
            assembly {
                let returnData_size := mload(returnData)
                revert(add(32, returnData), returnData_size)
            }
        } else {
            revert(error);
        }
    }
}

// File: contracts/interfaces/IERC173.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

import { IERC173Internal } from './IERC173Internal.sol';

/**
 * @title Contract ownership standard interface
 * @dev see https://eips.ethereum.org/EIPS/eip-173
 */
interface IERC173 is IERC173Internal {
    /**
     * @notice get the ERC173 contract owner
     * @return contract owner
     */
    function owner() external view returns (address);

    /**
     * @notice transfer contract ownership to new account
     * @param account address of new owner
     */
    function transferOwnership(address account) external;
}

// File: contracts/utils/UintUtils.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

/**
 * @title utility functions for uint256 operations
 * @dev derived from https://github.com/OpenZeppelin/openzeppelin-contracts/ (MIT license)
 */
library UintUtils {
    error UintUtils__InsufficientHexLength();

    bytes16 private constant HEX_SYMBOLS = '0123456789abcdef';

    function add(uint256 a, int256 b) internal pure returns (uint256) {
        return b < 0 ? sub(a, -b) : a + uint256(b);
    }

    function sub(uint256 a, int256 b) internal pure returns (uint256) {
        return b < 0 ? add(a, -b) : a - uint256(b);
    }

    function toString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return '0';
        }

        uint256 temp = value;
        uint256 digits;

        while (temp != 0) {
            digits++;
            temp /= 10;
        }

        bytes memory buffer = new bytes(digits);

        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }

        return string(buffer);
    }

    function toHexString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return '0x00';
        }

        uint256 length = 0;

        for (uint256 temp = value; temp != 0; temp >>= 8) {
            unchecked {
                length++;
            }
        }

        return toHexString(value, 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';

        unchecked {
            for (uint256 i = 2 * length + 1; i > 1; --i) {
                buffer[i] = HEX_SYMBOLS[value & 0xf];
                value >>= 4;
            }
        }

        if (value != 0) revert UintUtils__InsufficientHexLength();

        return string(buffer);
    }
}

// File: contracts/proxy/IProxy.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

interface IProxy {
    error Proxy__ImplementationIsNotContract();

    fallback() external payable;
}

// File: contracts/interfaces/IERC173Internal.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

/**
 * @title Partial ERC173 interface needed by internal functions
 */
interface IERC173Internal {
    event OwnershipTransferred(
        address indexed previousOwner,
        address indexed newOwner
    );
}