code: def __call__(self):
      batch = self._data[self._index]
      self._index = (self._index + 1) % self.batch_size()
      return batch
  
imports: import nvidia.dali.fn
  from nvidia.dali.pipeline import Pipeline
  from nose.tools import nottest
  import numpy
  from test_utils import np_type_to_dali
  from nose_utils import assert_raises
label_desc: Use image node_id 2 for calling the Batch obj's underlying member method code with example usage: obj.__call__() and returns: batch