code: def put(self, item):
          
          uid = str(uuid.uuid4())
  
          if self.serializer is not None:
              item = self.serializer.dumps(item)
  
          self._redis.pipeline()\
                  .hset(self.ITEMS_KEY, uid, item)\
                  .lpush(self.QUEUE_KEY, uid)\
                  .execute()
          return uid
docs: Adds an item to the queue.
  
          Generates a uid for later referral.
          Enqueues the uid and stores the item.