private static function _header($title = null): string
    {
        switch (self::$type) {
            case 'xspf':
                $header = "<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n<playlist version = \"1\" xmlns=\"http://xspf.org/ns/0/\">\n<title>" . ($title ?? T_("Ampache XSPF Playlist")) . "</title>\n<creator>" . scrub_out(AmpConfig::get('site_title')) . "</creator>\n<annotation>" . scrub_out(AmpConfig::get('site_title')) . "</annotation>\n<info>" . AmpConfig::get('web_path') . "</info>\n<trackList>\n";