public static function markdown(&$content)
    {
        if (self::$MarkdownParser === null) {
            if (class_exists('dflydev\markdown\MarkdownParser')) {
                self::$MarkdownParser = new \dflydev\markdown\MarkdownParser;
            } else {
                self::$MarkdownParser = false;
            }
        }

        if (self::$MarkdownParser !== false) {
            $content = trim(self::$MarkdownParser->transformMarkdown($content));
        }

        return $content;
    }