def __init__(self, ds, batch_size, queue=None):
        """
        Args:
            ds(DataFlow): the input DataFlow.
            batch_size(int): the batch size.
            queue (tf.QueueBase): A :class:`tf.QueueBase` whose type
                should match the corresponding input signature of the model.
                Defaults to a FIFO queue of size 3000.
        """
        super(BatchQueueInput, self).__init__(ds, queue)
        self.batch_size = int(batch_size)

        Args:
            ds(DataFlow): the input DataFlow.
            batch_size(int): the batch size.
            queue (tf.QueueBase): A :class:`tf.QueueBase` whose type
                should match the corresponding input signature of the model.
                Defaults to a FIFO queue of size 3000.
        
tensorpack/input_source/input_source.py