protected function readContent(/*# string */ $path)/*# : string */
    {
        $str = file_get_contents($path);

        if (is_string($str)) {
            return $str;
        } else {
            throw new LogicException(
                Message::get(Message::ENV_READ_FAIL, $path),
                Message::ENV_READ_FAIL
            );
        }
    }