상속: extends App\Http\Requests\Request
 /**
  * @param \App\Http\Requests\Front\NewsletterSubscriptionRequest $request
  *
  * @return \Illuminate\Http\JsonResponse
  */
 public function subscribe(NewsletterSubscriptionRequest $request)
 {
     $email = strtolower($request->get('email'));
     if (Newsletter::hasMember($email)) {
         return $this->respond(['message' => fragment('newsletter.subscription.result.alreadySubscribed'), 'type' => 'info']);
     }
     $result = Newsletter::subscribe($email);
     if (!$result) {
         return $this->respondWithBadRequest(['message' => fragment('newsletter.subscription.result.error'), 'type' => 'error']);
     }
     activity()->log("{$email} schreef zich in op de nieuwsbrief");
     return $this->respond(['message' => fragment('newsletter.subscription.result.ok'), 'type' => 'success']);
 }