public function onBefore(BeforeEvent $event)
 {
     $request = $event->getRequest();
     if (isset(self::$purgeMethods[$request->getMethod()])) {
         $this->storage->purge($request);
     }
 }
 public function onBefore(BeforeEvent $event)
 {
     $request = $event->getRequest();
     if (isset(self::$purgeMethods[$request->getMethod()])) {
         $this->storage->purge($request->getUrl());
         if ('PURGE' === $request->getMethod()) {
             $event->intercept(new Response(204));
         }
     }
 }