// File: contracts/reserve/TeamVestingReserve.sol



// SPDX-License-Identifier: gpl-3.0

pragma solidity 0.7.5;

import './ManagedVestingReserve.sol';

/**
 * @title VestingReserveTest
 * @author Ethichub
 */
contract TeamVestingReserve is ManagedVestingReserve {
    constructor(
        IERC20 _token,
        uint256 _startTime,
        uint256 _endTime,
        uint256 _editAddressUntil
    ) ManagedVestingReserve(_token, _startTime, _endTime, _editAddressUntil) {}

    function initialize() external override {
        require(!initialized, 'TeamVestingReserve: Already initialized');
        require(
            token.transferFrom(msg.sender, address(this), 8870000*10**18),
            'ManagedVestingReserve: Cannot transfer tokens from sender.'
        );
        locked[0x7E032A1Bed85664209B3C22D12caec40fdF73089] = 130000*10**18;
        locked[0x0D8e931A2743Bfb50d1429EC1E73a466A4fa9BB0] = 110000*10**18;
        locked[0x59d35A531AA78FCAD3F1d06FAbE4C23a574B8d07] = 10000*10**18;
        locked[0x93204c3625091Dc552DEE3701CE7284B0510555c] = 20000*10**18;
        locked[0xA80cA7F9f08E755BC64D4aEd92EA714228774deF] = 100000*10**18;
        locked[0x967BFBaDa372B5EeCa46C8617a20279bF2bdf4bd] = 25000*10**18;
        locked[0x577cfE680652C4aa485dC723B308E5B60bF3D548] = 50000*10**18;
        locked[0x21B8B42988E658f3C6e481cD574892518792dF9d] = 50000*10**18;
        locked[0xc2053f86fe04DD2327aE5F05DB29818d84adDcd2] = 25000*10**18;
        locked[0x09381bA61fD003d25e6e947021e3274bFDC4771B] = 50000*10**18;
        locked[0xeaa7b78F364244648ACEEE35e4b244A4bBBEb9c6] = 75000*10**18;
        locked[0x5185B72571670C0Add34F8a1CDe591be5Db38587] = 75000*10**18;
        locked[0xDA2b4caCf6C3eC81fc54E1521ca916E010E41DB8] = 75000*10**18;
        locked[0x158e1D176fF937A8E6bFAA482179f876841539d2] = 75000*10**18;
        locked[0x29D7a84502392CF962ef3677fb1CF1cc55DAa006] = 5000*10**18;
        locked[0x8F1EFcD1898d4d0b0B5d1C8279719199907005D2] = 100000*10**18;
        locked[0x42d4B594ac3623e62f80C651c306aa3eA6D6B211] = 100000*10**18;
        locked[0xc1f0A5c6CFA9eDDa352336e9E8202BC097E72C68] = 80000*10**18;
        locked[0x359ac09D81D7F3D4DF8Efa11612E3dc19EAcF53d] = 80000*10**18;
        locked[0x75b2b8F4912b45Fea37B5D64500c990c6CCF9E47] = 100000*10**18;
        locked[0x4e835eae369095057A70bBb5716cF649941716AC] = 17500*10**18;
        locked[0x9D51743Cd824fd8C2F9e736E6a187d56Bf9b2F25] = 17500*10**18;
        locked[0x31ffeD317021D6fAac20ec097587bD36Fa15054B] = 17500*10**18;
        locked[0x3EFf9EB60c80C47e9d92ec7ACDD1135451eE8291] = 17500*10**18;
        locked[0x86e6Fd1441A06afb651707F7609966F5FFBfDbD4] = 10000*10**18;
        locked[0x84e26011d1Db5A4c3be1c9E465b5aE659229C075] = 50000*10**18;
        locked[0x6Cb87e0E835d0842a7d19bFdB5B91C449b71998B] = 70000*10**18;
        locked[0xB4FBF73b4C537Bf032d62e2069946E3A347a2c43] = 30000*10**18;
        locked[0x8FC47DE24f4bDb4f29e1dB7CDF64A173C3dF8242] = 60000*10**18;
        locked[0xE75a4B67DE2012e4c3D0ae7D4D7ef9Aa070aEE26] = 90000*10**18;
        locked[0xa601A7c91ba1eD992b897f9ACfA02D6E688d6161] = 120000*10**18;
        locked[0x2017864F4D7e4D7EDC829beB3d6d3dA64AE6a1d0] = 100000*10**18;
        locked[0x70bB5b88A047ECEAf9C4d5803e9BA6D7e4B57B9B] = 20000*10**18;
        locked[0x4e7f2dEf792A9e2Ea8AE37e2696F2a6040cC1B1a] = 50000*10**18;
        locked[0x587d43D668868C954622bAC0bfc07977Ded0fD76] = 250000*10**18;
        locked[0xE67435869ADFEda294EEae3344fE744016D42dcE] = 270000*10**18;
        locked[0x08bC79Fd10A6077339D74CD09FB26fCa6702d035] = 280000*10**18;
        locked[0xBC3B7EF402762b7118016B63CFa4cdC7653fBBd3] = 300000*10**18;
        locked[0xC9e458fE112c23b2d6f8bE8660001d272a7BA971] = 10000*10**18;
        locked[0xf4ef544BbDf4E90218Bc703E9e97Ee1f6e167152] = 30000*10**18;
        locked[0xbC0B3B66F3B8e89cd842E2f809947989e6154158] = 5000*10**18;
        locked[0x7aE0FD06c57da7a821494032ec0e9F67e5014722] = 150000*10**18;
        locked[0x343448DfA1a856580C07882107986F1244C30E06] = 20000*10**18;
        locked[0xD234125A204a75cf35314Fb541D028911EFdA21d] = 50000*10**18;
        locked[0xaa60084B1170bce4b6AaA1c56C1AA5f3DCA85923] = 100000*10**18;
        locked[0x1EbfD92F36FbD05349cBA41745B25fdcf378A296] = 425000*10**18;
        locked[0x19fBD61409e6c3d4D7110B959147D3D26D5F287F] = 250000*10**18;
        locked[0xdFe435e074E9830036aeA0eA5C4fC506b7a11D5f] = 250000*10**18;
        locked[0xb7b3279236803Ccf3C353cB7B683A3d92D709D9c] = 100000*10**18;
        locked[0xe5a6301fA182EE9504485d61e4Ac0DadDf2F5b13] = 500000*10**18;
        locked[0x25090352F2cC84819F80B20DC699B282f58e782E] = 175000*10**18;
        locked[0x90299EC59b94398a3a31a795Bc585F743d0e5Cc9] = 500000*10**18;
        locked[0xFF3e42196A601037690CD114955D6aAA7239FdcF] = 500000*10**18;
        locked[0x8BDC3d98A267020F80936E4FF18f279b611452c3] = 400000*10**18;
        locked[0x36711AbC93b49f213929D79b031226f380BA600b] = 350000*10**18;
        locked[0x23657E0AF50F8A2079a47a76ab014437E8104840] = 250000*10**18;
        locked[0x14F9eA19346aAdf614bFA125c0C7b8156D05a192] = 200000*10**18;
        locked[0x893c28FF9DDcef2789897eD6F8179748422f0aB7] = 150000*10**18;
        locked[0x1E60c67Dd5ae48Ae59aE60e26d070cDd42F0e29f] = 100000*10**18;
        locked[0x5F0B6C0A1DD7413E6A213e81a59d34da52016957] = 50000*10**18;
        locked[0xc1f0A5c6CFA9eDDa352336e9E8202BC097E72C68] = 300000*10**18;
        locked[0xEbe8763e0D0c6372CcD30A1e8856C0F653B98f06] = 100000*10**18;
        locked[0x271DBF87f8689f231012168eA7add80202554f5b] = 100000*10**18;
        locked[0x881b5B76c6dFb303E03572D63Bf1aBD9c3ac6e7E] = 100000*10**18;
        locked[0x5ED50FC239911f55C41E333dCc9d5682Ff3db1F7] = 100000*10**18;
        locked[0x894469D0Da61A2c92d45405488AD3A2B90704a78] = 100000*10**18;
        locked[0x9EDde74078Fba110c22922a925f653BCF1F60121] = 100000*10**18;
        locked[0x090DF5DD1028921a51234Eb1d8fb0ccF03210c95] = 100000*10**18;
        locked[0xe592CC21910769477a06b4B8E89df055bD862475] = 100000*10**18;
        locked[0x94a13849b08f760B058d36ba56866764Ec182837] = 100000*10**18;

        initialized = true;
    }
}

// File: contracts/reserve/ManagedVestingReserve.sol



// SPDX-License-Identifier: gpl-3.0

pragma solidity 0.7.5;
import './VestingReserve.sol';

/**
 * @title VestingReserve
 * @dev A vested reserve, freeing 1% per day
 * @author Ethichub
 */
abstract contract ManagedVestingReserve is VestingReserve {
    constructor(
        IERC20 _token,
        uint256 _startTime,
        uint256 _endTime,
        uint256 _editAddressUntil
    ) VestingReserve(_token, _startTime, _endTime, _editAddressUntil) {}

    function claim(uint256 _amount) external override {
        revert('ManagedVestingReserve: Unsupported method');
    }
}

// File: contracts/reserve/VestingReserve.sol



// SPDX-License-Identifier: gpl-3.0

pragma solidity 0.7.5;

import '@openzeppelin/contracts/access/Ownable.sol';
import '@openzeppelin/contracts/math/SafeMath.sol';
import '@openzeppelin/contracts/token/ERC20/IERC20.sol';
import '@openzeppelin/contracts/token/ERC20/SafeERC20.sol';


/**
 * @title VestingReserve
 * @dev A vested reserve, freeing 1% per day
 * @author Ethichub
 */
contract VestingReserve is Ownable {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;

    IERC20 public token;

    bool public initialized;

    // Dates
    uint256 public startTime;
    uint256 public endTime;
    uint256 public editAddressUntil;

    // Amounts
    mapping(address => uint256) public locked;
    mapping(address => uint256) public claimed;

    // Events
    event Fund(address indexed recipient, uint256 amount);
    event Claim(address indexed recipient, uint256 claimed);
    event ToggleDisable(address recipient, bool disabled);
    event ChangeTokenOwnership(address _account, address indexed _newAccount);

    modifier isInitialized() {
        require(initialized, 'VestingReserve: Contract not initialized');
        _;
    }

    constructor(
        IERC20 _token,
        uint256 _startTime,
        uint256 _endTime,
        uint256 _editAddressUntil
    ) {
        token = _token;
        require(_endTime > _startTime, 'VestingReserve: end time must be later than start time');
        startTime = _startTime;
        endTime = _endTime;
        require(_editAddressUntil <= _endTime, 'VestingReserve: _editAddressUntil time should be before than end time');
        editAddressUntil = _editAddressUntil;
    }

    function initialize() external virtual {}

    function _vestedOf(address _account) internal view returns (uint256) {
        if (block.timestamp < startTime) {
            return 0;
        } else if (block.timestamp > endTime) {
            return locked[_account];
        } else if (locked[_account] == 0) {
            return 0;
        }

        uint256 amountLocked = locked[_account];

        uint256 vested =
            (amountLocked.mul(block.timestamp.sub(startTime)).div(endTime.sub(startTime)));
        if (vested > amountLocked) {
            return amountLocked;
        } else {
            return vested;
        }
    }

    function _lockedOf(address _account) internal view returns (uint256) {
        return locked[_account].sub(_vestedOf(_account));
    }

    function changeTokenOwnership(address _account, address _newAccount)
        virtual
        public
        isInitialized
        onlyOwner
    {
        require(
            block.timestamp <= editAddressUntil,
            'VestingReserve: Expired date to change token ownership'
        );
        locked[_newAccount] = locked[_account];
        claimed[_newAccount] = claimed[_account];
        locked[_account] = 0;
        claimed[_account] = 0;
        emit ChangeTokenOwnership(_account, _newAccount);
    }

    function _claim(address _account, uint256 _amount) internal {
        uint256 claimable = _vestedOf(_account).sub(claimed[_account]);
        require(claimable > 0, 'VestingReserve: No tokens to transfer');
        require(_amount > 0, 'VestingReserve: Amount cannot be zero');

        if (_amount > claimable) {
            _amount = claimable;
        }

        claimed[_account] = claimed[_account].add(_amount);
        token.safeTransfer(_account, _amount);
        emit Claim(_account, _amount);
    }

    function claim(uint256 _amount) external virtual isInitialized {
        _claim(msg.sender, _amount);
    }

    function claimFor(address _account, uint256 _amount) external isInitialized onlyOwner {
        _claim(_account, _amount);
    }

    function vestedOf(address _account) external view isInitialized returns (uint256) {
        return _vestedOf(_account);
    }

    function lockedOf(address _account) external view isInitialized returns (uint256) {
        return locked[_account].sub(_vestedOf(_account));
    }
}

// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.7.0;

import "../GSN/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 () {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(_owner == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = 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");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

// File: @openzeppelin/contracts/math/SafeMath.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.7.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts with custom message when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

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



// SPDX-License-Identifier: MIT

pragma solidity ^0.7.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

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

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

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

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

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

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

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

// File: @openzeppelin/contracts/token/ERC20/SafeERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.7.0;

import "./IERC20.sol";
import "../../math/SafeMath.sol";
import "../../utils/Address.sol";

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using SafeMath for uint256;
    using Address for address;

    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(IERC20 token, address spender, uint256 value) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        // solhint-disable-next-line max-line-length
        require((value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).add(value);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) { // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

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



// SPDX-License-Identifier: MIT

pragma solidity ^0.7.0;

/*
 * @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 GSN 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 payable) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

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



// SPDX-License-Identifier: MIT

pragma solidity ^0.7.0;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // According to EIP-1052, 0x0 is the value returned for not-yet created accounts
        // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
        // for accounts without code, i.e. `keccak256('')`
        bytes32 codehash;
        bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
        // solhint-disable-next-line no-inline-assembly
        assembly { codehash := extcodehash(account) }
        return (codehash != accountHash && codehash != 0x0);
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{ value: amount }("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain`call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
      return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        return _functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        return _functionCallWithValue(target, data, value, errorMessage);
    }

    function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {
        require(isContract(target), "Address: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}