/**
  * @param AdaptFormEvent $event
  */
 public function adaptForm(AdaptFormEvent $event)
 {
     /** @var HasMediaSetInterface $page */
     $page = $event->getPage();
     if (false === $page instanceof HasMediaSetInterface) {
         return;
     }
     $mediaSet = $this->repository->getPageMediaSet($page);
     $type = new PageMediaCollectionAdminType($page, $this->mediaSetDefinition);
     $mediaWidget = new FormWidget($type, new ArrayCollection($mediaSet));
     $event->getTabPane()->addTab(new Tab('Media Set', $mediaWidget));
 }