Update docs

modules/lesson_embeds/src/EventSubscriber/RemoveXFrameOptionsSubscriber.php

@@ -8,13 +8,21 @@ use Symfony\Component\HttpKernel\KernelEvents;
 
 class RemoveXFrameOptionsSubscriber implements EventSubscriberInterface {
 
+  /**
+   * Executes actions on the respose event.
+   *
+   * @param \Symfony\Component\HttpKernel\Event\FilterResponseEvent $event
+   *   Filter Response Event object.
+   */
   public function RemoveXFrameOptions(FilterResponseEvent $event) {
     $response = $event->getResponse();
-    $response->headers->remove('X-Frame-Options');
     $response->headers->set('X-Frame-Options', 'ALLOW-FROM https://psu.instructure.com/');
     $response->headers->set('Content-Security-Policy', 'frame-ancestors https://psu.instructure.com/');
   }
 
+  /**
+   * {@inheritdoc}
+   */
   public static function getSubscribedEvents() {
     $events[KernelEvents::RESPONSE][] = array('RemoveXFrameOptions', -10);
     return $events;