code: def _PrintGrad(op, *grad):
      return list(grad) + [None] * (len(op.inputs) - 1)
  
imports: import collections
  import os
  import pprint
  import random
  import sys
  from absl import logging
  from tensorflow.python import pywrap_tfe
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import sparse_tensor
  from tensorflow.python.framework import tensor_util
  from tensorflow.python.ops import gen_logging_ops
  from tensorflow.python.ops import string_ops
  from tensorflow.python.ops.gen_logging_ops import *
  from tensorflow.python.platform import tf_logging
  from tensorflow.python.util import dispatch
  from tensorflow.python.util import nest
  from tensorflow.python.util.deprecation import deprecated
  from tensorflow.python.util.tf_export import tf_export
label_desc: Use image node_id 6 for calling a global function with example usage: _PrintGrad(op) and returns: unknown