'Args:
input (DataFlow or QueueInput)
gpus (list[int]): list of GPU id'

def __init__(self, input, infs, gpus):

    self._tower_names = ['InferenceTower{}'.format(k) for k in range(len(gpus))]
    if isinstance(input, DataFlow):
        input = QueueInput(input)
    assert isinstance(input, QueueInput), input
    super(DataParallelInferenceRunner, self).__init__(input, infs)
    self._gpus = gpus
