code: def _unstack_nested_arrays_into_flat_item_iterator(nested_array):
      def _unstack(array):
          # Use numpy views instead of np.split, it's 5x+ faster.
          return [array[i] for i in range(len(array))]
  
      return zip(
          *[_unstack(array) for array in tf.nest.flatten(nested_array)]
      )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import collections
  import numbers
  from typing import Optional, Text
  from absl import logging
  import numpy
  from six.moves import zip
  import tensorflow
  from tf_agents.typing import types
  from tf_agents.utils import composite
  import wrapt
  from tensorflow.python.util import nest
label_desc: Use image node_id 27 for calling a global function with example usage: _unstack_nested_arrays_into_flat_item_iterator(nested_array) and returns: zip, unknown