transfer.js

    function verifyTransfer(address _from, address _to, uint256 _amount) public view returns (bool success) {
        return true;
    }

    /**
     * @dev Overloaded version of the transfer function
     */
    function transfer(address _to, uint256 _value) public returns (bool success) {
        require(verifyTransfer(msg.sender, _to, _value));
        return super.transfer(_to, _value);
    }

    /**
     * @dev Overloaded version of the transferFrom function
     */
    function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) {
        require(verifyTransfer(_from, _to, _value));
        return super.transferFrom(_from, _to, _value);
    }