public function getList(): array {
        $list = array();
        $dir = $this->_docRoot . $this->_path;
        if (is_dir($dir)) {
            if ($dh = opendir($dir)) {
                while (($file = readdir($dh)) !== false) {
                    if (substr($file, 0, 1) !== '.'
                        && strpos($file, '.') !== false
                    ) {
                        $list[] = $file;
                    }
                }
                closedir($dh);
            }
        } else {
            throw new Exception($dir . ' is not a directory.');
        }

        return $list;
    }