/**
  * Get middleware bag.
  *
  * @param Route $route
  *
  * @return ParameterBagInterface|null
  */
 private function getMiddlewareBag(Route $route)
 {
     if ($route->hasBag('middlewares') && null !== ($bag = $route->getBag('middlewares'))) {
         return $bag;
     }
     return null;
 }