def queueStream(self, rdds, oneAtATime=True, default=None):
        """Create stream iterable over RDDs.

        :param rdds: Iterable over RDDs or lists.
        :param oneAtATime: Process one at a time or all.
        :param default: If no more RDDs in ``rdds``, return this. Can be None.
        :rtype: DStream


        Example:

        >>> import pysparkling
        >>> sc = pysparkling.Context()
        >>> ssc = pysparkling.streaming.StreamingContext(sc, 0.1)
        >>> (
        ...     ssc
        ...     .queueStream([[4], [2], [7]])
        ...     .foreachRDD(lambda rdd: print(rdd.collect()))
        ... )
        >>> ssc.start()
        >>> ssc.awaitTermination(0.35)
        [4]
        [2]
        [7]


        Example testing the default value:

        >>> import pysparkling
        >>> sc = pysparkling.Context()
        >>> ssc = pysparkling.streaming.StreamingContext(sc, 0.1)
        >>> (
        ...     ssc
        ...     .queueStream([[4], [2]], default=['placeholder'])
        ...     .foreachRDD(lambda rdd: print(rdd.collect()))
        ... )
        >>> ssc.start()
        >>> ssc.awaitTermination(0.35)
        [4]
        [2]
        ['placeholder']
        """
        deserializer = QueueStreamDeserializer(self._context)
        if default is not None:
            default = deserializer(default)

        if Queue is False:
            log.error('Run "pip install tornado" to install tornado.')

        q = Queue()
        for i in rdds:
            q.put(i)

        qstream = QueueStream(q, oneAtATime, default)
        return DStream(qstream, self, deserializer)
Create stream iterable over RDDs.

        :param rdds: Iterable over RDDs or lists.
        :param oneAtATime: Process one at a time or all.
        :param default: If no more RDDs in ``rdds``, return this. Can be None.
        :rtype: DStream


        Example:

        >>> import pysparkling
        >>> sc = pysparkling.Context()
        >>> ssc = pysparkling.streaming.StreamingContext(sc, 0.1)
        >>> (
        ...     ssc
        ...     .queueStream([[4], [2], [7]])
        ...     .foreachRDD(lambda rdd: print(rdd.collect()))
        ... )
        >>> ssc.start()
        >>> ssc.awaitTermination(0.35)
        [4]
        [2]
        [7]


        Example testing the default value:

        >>> import pysparkling
        >>> sc = pysparkling.Context()
        >>> ssc = pysparkling.streaming.StreamingContext(sc, 0.1)
        >>> (
        ...     ssc
        ...     .queueStream([[4], [2]], default=['placeholder'])
        ...     .foreachRDD(lambda rdd: print(rdd.collect()))
        ... )
        >>> ssc.start()
        >>> ssc.awaitTermination(0.35)
        [4]
        [2]
        ['placeholder']