class_docstr: Tests for NodeFileWriter.
code: def _get_input_tensor(self, node_def, input_index):
      tensor_proto = node_def.attr.get(f"_input_tensor_{input_index}")
      if tensor_proto is None:
          return None
      return tensor_util.MakeNdarray(tensor_proto.tensor)
  
imports: import io
  import os
  import struct
  import tempfile
  import numpy
  from tensorflow.core.framework import node_def_pb2
  from tensorflow.python.eager import context
  from tensorflow.python.framework import config
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import tensor_util
  from tensorflow.python.framework import test_util
  from tensorflow.python.framework.test_util import IsMklEnabled
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import gen_array_ops
  from tensorflow.python.ops import gen_math_ops
  from tensorflow.python.ops import gen_nn_ops
  from tensorflow.python.platform import test
label_desc: Use image node_id 8 for calling the NodeFileWriterTest obj's underlying member method code with example usage: obj._get_input_tensor(node_def, input_index) and returns: tensor_util, None