code: def _get(self, *args, **kwargs):
          
          messages, all_retrieved = super(StorageMixin, self)._get(*args, **kwargs)
          if self.user.is_authenticated():
              inbox_messages = self.backend.inbox_list(self.user)
          else:
              inbox_messages = []
  
          return messages + inbox_messages, all_retrieved
docs: Retrieve unread messages for current user, both from the inbox and
          from other storages