pragma solidity ^0.5.0;


interface IERC20 {
    
    function totalSupply() external view returns (uint256);

    
    function balanceOf(address account) external view returns (uint256);

    
    function transfer(address recipient, uint256 amount) external returns (bool);

    
    function allowance(address owner, address spender) external view returns (uint256);

    
    function approve(address spender, uint256 amount) external returns (bool);

    
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    
    event Transfer(address indexed from, address indexed to, uint256 value);

    
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

library SafeMath {
    
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SafeMath: subtraction overflow");
        uint256 c = a - b;

        return c;
    }

    
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        
        
        
        if (a == 0) {
            return 0;
        }

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

        return c;
    }

    
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        
        require(b > 0, "SafeMath: division by zero");
        uint256 c = a / b;
        

        return c;
    }

    
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b != 0, "SafeMath: modulo by zero");
        return a % b;
    }
}

library Address {
    
    function isContract(address account) internal view returns (bool) {
        
        
        

        uint256 size;
        
        assembly { size := extcodesize(account) }
        return size > 0;
    }
}

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));
    }

    function safeApprove(IERC20 token, address spender, uint256 value) internal {
        
        
        
        
        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);
        callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    
    function callOptionalReturn(IERC20 token, bytes memory data) private {
        
        

        
        
        
        
        
        require(address(token).isContract(), "SafeERC20: call to non-contract");

        
        (bool success, bytes memory returndata) = address(token).call(data);
        require(success, "SafeERC20: low-level call failed");

        if (returndata.length > 0) { 
            
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

contract TokenTimelock {
    using SafeERC20 for IERC20;

    
    IERC20 private _token;

    
    address private _beneficiary;

    
    uint256 private _releaseTime;

    constructor (IERC20 token, address beneficiary, uint256 releaseTime) public {
        
        require(releaseTime > block.timestamp, "TokenTimelock: release time is before current time");
        _token = token;
        _beneficiary = beneficiary;
        _releaseTime = releaseTime;
    }

    
    function token() public view returns (IERC20) {
        return _token;
    }

    
    function beneficiary() public view returns (address) {
        return _beneficiary;
    }

    
    function releaseTime() public view returns (uint256) {
        return _releaseTime;
    }

    
    function release() public {
        
        require(block.timestamp >= _releaseTime, "TokenTimelock: current time is before release time");

        uint256 amount = _token.balanceOf(address(this));
        require(amount > 0, "TokenTimelock: no tokens to release");

        _token.safeTransfer(_beneficiary, amount);
    }
}

contract TokenTimelockTest is TokenTimelock {
    constructor () public TokenTimelock(
        IERC20(0x9da1659a203cEfE6E9C6da98C7a669a1eC3D7EdE), 
        0xEfF3cb55501f1214A3f495A2B3575260D66eAD30, 
        1568545200) {
    }
}