Response::macro PHP Method

        public static function macro($name, $macro)
        {
            \Illuminate\Routing\ResponseFactory::macro($name, $macro);
        }

 private function make_xml()
 {
     Response::macro('xml', function (array $vars, $status = 200, array $headers = [], $xml = null) {
         $xml_out = self::create_xml($xml, $vars);
         if (empty($headers)) {
             $headers = self::handle();
         }
         return Response::make($xml_out->asXML(), $status, $headers);
     });
 }