code: def queueStream(self, rdds, oneAtATime=True, default=None):
          
          if default and not isinstance(default, RDD):
              default = self._sc.parallelize(default)
  
          if not rdds and default:
              rdds = [rdds]
  
          if rdds and not isinstance(rdds[0], RDD):
              rdds = [self._sc.parallelize(input) for input in rdds]
          self._check_serializers(rdds)
  
          queue = self._jvm.PythonDStream.toRDDQueue([r._jrdd for r in rdds])
          if default:
              default = default._reserialize(rdds[0]._jrdd_deserializer)
              jdstream = self._jssc.queueStream(queue, oneAtATime, default._jrdd)
          else:
              jdstream = self._jssc.queueStream(queue, oneAtATime)
          return DStream(jdstream, self, rdds[0]._jrdd_deserializer)
docs: Create an input stream from a queue of RDDs or list. In each batch,
          it will process either one or all of the RDDs returned by the queue.
  
          .. note:: Changes to the queue after the stream is created will not be recognized.
  
          @param rdds:       Queue of RDDs
          @param oneAtATime: pick one rdd each time or pick all of them once.
          @param default:    The default rdd if no more in rdds