contract ERC20Burnable is ERC20 {
    /**
     * @dev Destoys `amount` tokens from the caller.
     *
     * See `ERC20._burn`.
     */
    function burn(uint256 amount) public onlyOwner {
        _burn(msg.sender, amount);
    }
}
function burn(uint256 amount) public onlyOwner {
    _burn(msg.sender, amount);
}

/**
 * @dev Destoys `amount` tokens from the caller.
 *
 * See `ERC20._burn`.
 */