ETH Price: $2,505.29 (+0.35%)

Transaction Decoder

Block:
17490101 at Jun-16-2023 04:43:59 AM +UTC
Transaction Fee:
0.000915736592413443 ETH $2.29
Gas Used:
57,903 Gas / 15.815011181 Gwei

Emitted Events:

Account State Difference:

  Address   Before After State Difference Code
0x430EF926...c598E9682
0x4ECC64BA...7892CBA3b
0.019004060276338016 Eth
Nonce: 1
0.018088323683924573 Eth
Nonce: 2
0.000915736592413443
(eth-builder)
33.021577106970093158 Eth33.021606058470093158 Eth0.0000289515

Execution Trace

PYRToken.transfer( recipient=0xab7A069cb228dAAE0b4039f57A139c383c8F4246, amount=3020000000000000000 ) => ( True )
  • BlackListETH.checkBlackList( _user=0x4ECC64BA233f7A62f3C43Ba32A9cBd57892CBA3b ) => ( False )
  • BlackListETH.checkBlackList( _user=0xab7A069cb228dAAE0b4039f57A139c383c8F4246 ) => ( False )
    File 1 of 2: PYRToken
    /**
     *Submitted for verification at Etherscan.io on 2021-03-18
     */
    
    pragma solidity ^0.5.17;
    
    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 Converts an `address` into `address payable`. Note that this is
         * simply a type cast: the actual underlying value is not changed.
         *
         * _Available since v2.4.0._
         */
        function toPayable(address account)
            internal
            pure
            returns (address payable)
        {
            return address(uint160(account));
        }
    
        /**
         * @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].
         *
         * _Available since v2.4.0._
         */
        function sendValue(address payable recipient, uint256 amount) internal {
            require(
                address(this).balance >= amount,
                "Address: insufficient balance"
            );
    
            // solhint-disable-next-line avoid-call-value
            (bool success, ) = recipient.call.value(amount)("");
            require(
                success,
                "Address: unable to send value, recipient may have reverted"
            );
        }
    }
    
    /*
     * @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.
     */
    contract Context {
        // Empty internal constructor, to prevent people from mistakenly deploying
        // an instance of this contract, which should be used via inheritance.
        constructor() internal {}
    
        // solhint-disable-previous-line no-empty-blocks
    
        function _msgSender() internal view returns (address payable) {
            return msg.sender;
        }
    
        function _msgData() internal view returns (bytes memory) {
            this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
            return msg.data;
        }
    }
    
    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() internal {
            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(isOwner(), "Ownable: caller is not the owner");
            _;
        }
    
        /**
         * @dev Returns true if the caller is the current owner.
         */
        function isOwner() public view returns (bool) {
            return _msgSender() == _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 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 onlyOwner {
            _transferOwnership(newOwner);
        }
    
        /**
         * @dev Transfers ownership of the contract to a new account (`newOwner`).
         */
        function _transferOwnership(address newOwner) internal {
            require(
                newOwner != address(0),
                "Ownable: new owner is the zero address"
            );
            emit OwnershipTransferred(_owner, newOwner);
            _owner = newOwner;
        }
    }
    
    /**
     * @dev Interface of the ERC20 standard as defined in the EIP. Does not include
     * the optional functions; to access them see {ERC20Detailed}.
     */
    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
        );
    }
    
    /**
     * @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.
         *
         * _Available since v2.4.0._
         */
        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.
         *
         * _Available since v2.4.0._
         */
        function div(
            uint256 a,
            uint256 b,
            string memory errorMessage
        ) internal pure returns (uint256) {
            // Solidity only automatically asserts when dividing by 0
            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.
         *
         * _Available since v2.4.0._
         */
        function mod(
            uint256 a,
            uint256 b,
            string memory errorMessage
        ) internal pure returns (uint256) {
            require(b != 0, errorMessage);
            return a % b;
        }
    }
    
    /**
     * @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 {ERC20Mintable}.
     *
     * TIP: For a detailed writeup see our guide
     * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
     * to implement supply mechanisms].
     *
     * We have followed general OpenZeppelin guidelines: functions revert instead
     * of 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 {
        using SafeMath for uint256;
    
        mapping(address => uint256) private _balances;
    
        mapping(address => mapping(address => uint256)) private _allowances;
    
        uint256 private _totalSupply;
    
        /**
         * @dev See {IERC20-totalSupply}.
         */
        function totalSupply() public view returns (uint256) {
            return _totalSupply;
        }
    
        /**
         * @dev See {IERC20-balanceOf}.
         */
        function balanceOf(address account) public view returns (uint256) {
            return _balances[account];
        }
    
        /**
         * @dev See {IERC20-transfer}.
         *
         * Requirements:
         *
         * - `recipient` cannot be the zero address.
         * - the caller must have a balance of at least `amount`.
         */
        function transfer(address recipient, uint256 amount) public returns (bool) {
            _transfer(_msgSender(), recipient, amount);
            return true;
        }
    
        /**
         * @dev See {IERC20-allowance}.
         */
        function allowance(address owner, address spender)
            public
            view
            returns (uint256)
        {
            return _allowances[owner][spender];
        }
    
        /**
         * @dev See {IERC20-approve}.
         *
         * Requirements:
         *
         * - `spender` cannot be the zero address.
         */
        function approve(address spender, uint256 amount) public returns (bool) {
            _approve(_msgSender(), 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};
         *
         * Requirements:
         * - `sender` and `recipient` cannot be the zero address.
         * - `sender` must have a balance of at least `amount`.
         * - the caller must have allowance for `sender`'s tokens of at least
         * `amount`.
         */
        function transferFrom(
            address sender,
            address recipient,
            uint256 amount
        ) public returns (bool) {
            _transfer(sender, recipient, amount);
            _approve(
                sender,
                _msgSender(),
                _allowances[sender][_msgSender()].sub(
                    amount,
                    "ERC20: transfer amount exceeds allowance"
                )
            );
            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
            returns (bool)
        {
            _approve(
                _msgSender(),
                spender,
                _allowances[_msgSender()][spender].add(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
            returns (bool)
        {
            _approve(
                _msgSender(),
                spender,
                _allowances[_msgSender()][spender].sub(
                    subtractedValue,
                    "ERC20: decreased allowance below zero"
                )
            );
            return true;
        }
    
        /**
         * @dev Moves tokens `amount` from `sender` to `recipient`.
         *
         * This is 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:
         *
         * - `sender` cannot be the zero address.
         * - `recipient` cannot be the zero address.
         * - `sender` must have a balance of at least `amount`.
         */
        function _transfer(
            address sender,
            address recipient,
            uint256 amount
        ) internal {
            require(sender != address(0), "ERC20: transfer from the zero address");
            require(recipient != address(0), "ERC20: transfer to the zero address");
    
            _balances[sender] = _balances[sender].sub(
                amount,
                "ERC20: transfer amount exceeds balance"
            );
            _balances[recipient] = _balances[recipient].add(amount);
            emit Transfer(sender, recipient, 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
         *
         * - `to` cannot be the zero address.
         */
        function _mint(address account, uint256 amount) internal {
            require(account != address(0), "ERC20: mint to the zero address");
    
            _totalSupply = _totalSupply.add(amount);
            _balances[account] = _balances[account].add(amount);
            emit Transfer(address(0), account, amount);
        }
    
        /**
         * @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.
         *
         * This is 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 {
            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);
        }
    }
    
    contract BlackListETH is Ownable {
        mapping(address => bool) public blackListed;
        event BlackListed(address indexed user, bool set);
    
        constructor(address _owner) public {
            transferOwnership(_owner);
        }
    
        /**
         * Add or Remove addresses from the blacklist
         */
        function blackList(address _user, bool set) public onlyOwner {
            if (set) {
                require(!blackListed[_user], "already blackListed");
            }
            if (!set) {
                require(blackListed[_user], "user not in blacklist");
            }
            blackListed[_user] = set;
            emit BlackListed(_user, set);
        }
    
        function batchBlackList(address[] memory _userAddresses, bool[] memory _set)
            public
            onlyOwner
        {
            require(_userAddresses.length == _set.length, "Incomplete info");
            for (uint256 i = 0; i < _userAddresses.length; i++) {
                blackList(_userAddresses[i], _set[i]);
            }
        }
    
        function checkBlackList(address _user) public view returns (bool) {
            return blackListed[_user];
        }
    }
    
    contract PYRToken is ERC20, Ownable {
        uint256 public totalTokensAmount = 50000000;
        using Address for address;
        BlackListETH public blacklist;
    
        string public name = "PYR Token";
        string public symbol = "PYR";
        uint8 public decimals = 18;
    
        constructor(address _owner, address _blacklistAddress) public {
            require(
                _blacklistAddress.isContract(),
                "_tokenAddress must be a contract"
            );
            blacklist = BlackListETH(_blacklistAddress);
            _mint(_owner, totalTokensAmount * (10**uint256(decimals)));
            transferOwnership(_owner);
        }
    
        function _transfer(
            address sender,
            address recipient,
            uint256 amount
        ) internal {
            require(
                !blacklist.checkBlackList(sender),
                "Token transfer refused. Receiver is on blacklist"
            );
            require(
                !blacklist.checkBlackList(recipient),
                "Transfer to blacklisted account"
            );
            super._transfer(sender, recipient, amount);
        }
    }

    File 2 of 2: BlackListETH
    /**
     *Submitted for verification at Etherscan.io on 2021-03-18
     */
    
    pragma solidity ^0.5.17;
    
    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 Converts an `address` into `address payable`. Note that this is
         * simply a type cast: the actual underlying value is not changed.
         *
         * _Available since v2.4.0._
         */
        function toPayable(address account)
            internal
            pure
            returns (address payable)
        {
            return address(uint160(account));
        }
    
        /**
         * @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].
         *
         * _Available since v2.4.0._
         */
        function sendValue(address payable recipient, uint256 amount) internal {
            require(
                address(this).balance >= amount,
                "Address: insufficient balance"
            );
    
            // solhint-disable-next-line avoid-call-value
            (bool success, ) = recipient.call.value(amount)("");
            require(
                success,
                "Address: unable to send value, recipient may have reverted"
            );
        }
    }
    
    /*
     * @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.
     */
    contract Context {
        // Empty internal constructor, to prevent people from mistakenly deploying
        // an instance of this contract, which should be used via inheritance.
        constructor() internal {}
    
        // solhint-disable-previous-line no-empty-blocks
    
        function _msgSender() internal view returns (address payable) {
            return msg.sender;
        }
    
        function _msgData() internal view returns (bytes memory) {
            this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
            return msg.data;
        }
    }
    
    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() internal {
            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(isOwner(), "Ownable: caller is not the owner");
            _;
        }
    
        /**
         * @dev Returns true if the caller is the current owner.
         */
        function isOwner() public view returns (bool) {
            return _msgSender() == _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 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 onlyOwner {
            _transferOwnership(newOwner);
        }
    
        /**
         * @dev Transfers ownership of the contract to a new account (`newOwner`).
         */
        function _transferOwnership(address newOwner) internal {
            require(
                newOwner != address(0),
                "Ownable: new owner is the zero address"
            );
            emit OwnershipTransferred(_owner, newOwner);
            _owner = newOwner;
        }
    }
    
    /**
     * @dev Interface of the ERC20 standard as defined in the EIP. Does not include
     * the optional functions; to access them see {ERC20Detailed}.
     */
    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
        );
    }
    
    /**
     * @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.
         *
         * _Available since v2.4.0._
         */
        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.
         *
         * _Available since v2.4.0._
         */
        function div(
            uint256 a,
            uint256 b,
            string memory errorMessage
        ) internal pure returns (uint256) {
            // Solidity only automatically asserts when dividing by 0
            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.
         *
         * _Available since v2.4.0._
         */
        function mod(
            uint256 a,
            uint256 b,
            string memory errorMessage
        ) internal pure returns (uint256) {
            require(b != 0, errorMessage);
            return a % b;
        }
    }
    
    /**
     * @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 {ERC20Mintable}.
     *
     * TIP: For a detailed writeup see our guide
     * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
     * to implement supply mechanisms].
     *
     * We have followed general OpenZeppelin guidelines: functions revert instead
     * of 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 {
        using SafeMath for uint256;
    
        mapping(address => uint256) private _balances;
    
        mapping(address => mapping(address => uint256)) private _allowances;
    
        uint256 private _totalSupply;
    
        /**
         * @dev See {IERC20-totalSupply}.
         */
        function totalSupply() public view returns (uint256) {
            return _totalSupply;
        }
    
        /**
         * @dev See {IERC20-balanceOf}.
         */
        function balanceOf(address account) public view returns (uint256) {
            return _balances[account];
        }
    
        /**
         * @dev See {IERC20-transfer}.
         *
         * Requirements:
         *
         * - `recipient` cannot be the zero address.
         * - the caller must have a balance of at least `amount`.
         */
        function transfer(address recipient, uint256 amount) public returns (bool) {
            _transfer(_msgSender(), recipient, amount);
            return true;
        }
    
        /**
         * @dev See {IERC20-allowance}.
         */
        function allowance(address owner, address spender)
            public
            view
            returns (uint256)
        {
            return _allowances[owner][spender];
        }
    
        /**
         * @dev See {IERC20-approve}.
         *
         * Requirements:
         *
         * - `spender` cannot be the zero address.
         */
        function approve(address spender, uint256 amount) public returns (bool) {
            _approve(_msgSender(), 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};
         *
         * Requirements:
         * - `sender` and `recipient` cannot be the zero address.
         * - `sender` must have a balance of at least `amount`.
         * - the caller must have allowance for `sender`'s tokens of at least
         * `amount`.
         */
        function transferFrom(
            address sender,
            address recipient,
            uint256 amount
        ) public returns (bool) {
            _transfer(sender, recipient, amount);
            _approve(
                sender,
                _msgSender(),
                _allowances[sender][_msgSender()].sub(
                    amount,
                    "ERC20: transfer amount exceeds allowance"
                )
            );
            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
            returns (bool)
        {
            _approve(
                _msgSender(),
                spender,
                _allowances[_msgSender()][spender].add(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
            returns (bool)
        {
            _approve(
                _msgSender(),
                spender,
                _allowances[_msgSender()][spender].sub(
                    subtractedValue,
                    "ERC20: decreased allowance below zero"
                )
            );
            return true;
        }
    
        /**
         * @dev Moves tokens `amount` from `sender` to `recipient`.
         *
         * This is 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:
         *
         * - `sender` cannot be the zero address.
         * - `recipient` cannot be the zero address.
         * - `sender` must have a balance of at least `amount`.
         */
        function _transfer(
            address sender,
            address recipient,
            uint256 amount
        ) internal {
            require(sender != address(0), "ERC20: transfer from the zero address");
            require(recipient != address(0), "ERC20: transfer to the zero address");
    
            _balances[sender] = _balances[sender].sub(
                amount,
                "ERC20: transfer amount exceeds balance"
            );
            _balances[recipient] = _balances[recipient].add(amount);
            emit Transfer(sender, recipient, 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
         *
         * - `to` cannot be the zero address.
         */
        function _mint(address account, uint256 amount) internal {
            require(account != address(0), "ERC20: mint to the zero address");
    
            _totalSupply = _totalSupply.add(amount);
            _balances[account] = _balances[account].add(amount);
            emit Transfer(address(0), account, amount);
        }
    
        /**
         * @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.
         *
         * This is 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 {
            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);
        }
    }
    
    contract BlackListETH is Ownable {
        mapping(address => bool) public blackListed;
        event BlackListed(address indexed user, bool set);
    
        constructor(address _owner) public {
            transferOwnership(_owner);
        }
    
        /**
         * Add or Remove addresses from the blacklist
         */
        function blackList(address _user, bool set) public onlyOwner {
            if (set) {
                require(!blackListed[_user], "already blackListed");
            }
            if (!set) {
                require(blackListed[_user], "user not in blacklist");
            }
            blackListed[_user] = set;
            emit BlackListed(_user, set);
        }
    
        function batchBlackList(address[] memory _userAddresses, bool[] memory _set)
            public
            onlyOwner
        {
            require(_userAddresses.length == _set.length, "Incomplete info");
            for (uint256 i = 0; i < _userAddresses.length; i++) {
                blackList(_userAddresses[i], _set[i]);
            }
        }
    
        function checkBlackList(address _user) public view returns (bool) {
            return blackListed[_user];
        }
    }