public function cssFile($path, $media = '') {
        if ('http' != substr($path, 0, 4)) {
            $path = \mpf\WebApp::get()->request()->getWebRoot() . $path;
        }
        $md5 = md5($path);
        if (in_array($md5, self::$cssScriptHistory))
            return '';
        self::$cssScriptHistory[] = $md5;
        if ($media !== '')
            $media = ' media="' . $media . '"';
        return '<link rel="stylesheet" type="text/css" href="' . self::encode($path) . '"' . $media . ' />';
    }