abstract contract ERC20Mintable is ERC20 {
    // indicates if minting is finished
    bool private _mintingFinished = false;

    /**
     * @dev Emitted during finish minting
     */
    event MintFinished();

    /**
     * @dev Tokens can be minted only before minting finished.
     */
    modifier canMint() {
        require(!_mintingFinished, "ERC20Mintable: minting is finished");
        _;
    }

    /**
     * @return if minting is finished or not.
     */
    function mintingFinished() public view returns (bool) {
        return _mintingFinished;
    }

    /**
     * @dev Function to mint tokens.
     *
     * WARNING: it allows everyone to mint new tokens. Access controls MUST be defined in derived contracts.
     *
     * @param account The address that will receive the minted tokens
     * @param amount The amount of tokens to mint
     */
    function mint(address account, uint256 amount) public canMint {
        _mint(account, amount);
    }

    /**
     * @dev Function to stop minting new tokens.
     *
     * WARNING: it allows everyone to finish minting. Access controls MUST be defined in derived contracts.
     */
    function finishMinting() public canMint {
        _finishMinting();
    }

    /**
     * @dev Function to stop minting new tokens.
     */
    function _finishMinting() internal virtual {
        _mintingFinished = true;

        emit MintFinished();
    }
}
/**
 * @title ERC20Mintable
 * @dev Implementation of the ERC20Mintable. Extension of {ERC20} that adds a minting behaviour.
 */
function mint(address account, uint256 amount) public canMint {
        _mint(account, amount);
    }
/**
 * @dev Function to mint tokens.
 *
 * WARNING: it allows everyone to mint new tokens. Access controls MUST be defined in derived contracts.
 *
 * @param account The address that will receive the minted tokens
 * @param amount The amount of tokens to mint
 */