code: def grouper(iterable, n, fillvalue=None):
      """Collect data into fixed-length chunks or blocks."""
      # grouper('ABCDEFG', 3, 'x') --> ABC DEF Gxx
      args = [iter(iterable)] * n
      return itertools.zip_longest(fillvalue=fillvalue, *args)
  
file_path: tensorflow/tensorflow/python/kernel_tests/nn_ops/ctc_decoder_ops_test.py
imports: import itertools
  import numpy
  from tensorflow.python.framework import errors
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops_stack
  from tensorflow.python.ops import ctc_ops
  from tensorflow.python.platform import test
label_desc: Use image node_id 1 for calling a global function with example usage: grouper(iterable, n, fillvalue) and returns: itertools