public static function get_url_id($url)
    {
        $service = self::identify_service($url);
        //TODO use a function for this, it is duplicated
        if ($service == self::YOUTUBE) {
            return self::get_youtube_id($url);
        } elseif ($service == self::VIMEO) {
            return self::get_vimeo_id($url);
        } elseif ($service == self::TWENTYTHREE) {
            return self::get_vimeo_id($url);
        }
        return null;
    }