protected function isFilesystemReadable(/*# string */ $path)/*# : bool */
    {
        if ($this->getFilesystem()->isReadable()) {
            return true;
        } else {
            return $this->setError(
                Message::get(Message::STR_FS_NONREADABLE, $path),
                Message::STR_FS_NONREADABLE
            );
        }
    }