/**
  * Export a Group in a Json file (.rzt).
  *
  * @param Symfony\Component\HttpFoundation\Request $request
  * @param int                                      $groupId
  *
  * @return Symfony\Component\HttpFoundation\Response
  */
 public function exportAction(Request $request, $groupId)
 {
     $this->validateAccessForRole('ROLE_ACCESS_GROUPS');
     $existingGroup = $this->getService('em')->find('RZ\\Roadiz\\Core\\Entities\\Group', (int) $groupId);
     $group = GroupCollectionJsonSerializer::serialize([$existingGroup]);
     $response = new Response($group, Response::HTTP_OK, []);
     $response->headers->set('Content-Disposition', $response->headers->makeDisposition(ResponseHeaderBag::DISPOSITION_ATTACHMENT, 'group-' . $existingGroup->getName() . '-' . date("YmdHis") . '.rzt'));
     // Rezo-Zero Type
     $response->prepare($request);
     return $response;
 }