@Override
 public void onResume() {
   super.onResume();
   eventBus.register(this);
   Optional<Chat> chat = userProfile.getChat(chatId);
   if (chat.isPresent() && !chat.get().messages.isEmpty()) {
     setData(chat.get());
   }
 }
 @Override
 public void onPause() {
   super.onPause();
   eventBus.unregister(this);
 }