code: def _ChainAllNodes(self, graph_def):
      return itertools.chain(
          graph_def.node,
          itertools.chain(
              *[func.node_def for func in graph_def.library.function]
          ),
      )
  
imports: import itertools
  import os
  from tensorflow.core.framework import attr_value_pb2
  from tensorflow.core.protobuf import saved_model_pb2
  from tensorflow.python.compiler.tensorrt import trt_convert
  from tensorflow.python.compiler.tensorrt.test import tf_trt_integration_test_base
  from tensorflow.python.compiler.tensorrt.test.tf_trt_integration_test_base import GraphState
  from tensorflow.python.compiler.tensorrt.test.tf_trt_integration_test_base import IsQuantizationWithCalibration
  from tensorflow.python.eager import def_function
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import tensor_spec
  from tensorflow.python.lib.io import file_io
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import nn
  from tensorflow.python.ops import nn_ops
  from tensorflow.python.platform import test
  from tensorflow.python.platform import tf_logging
  from tensorflow.python.saved_model import constants
  from tensorflow.python.saved_model import loader_impl
  from tensorflow.python.util import compat
label_desc: Use image node_id 4 for calling the TfFunctionTest obj's underlying member method code with example usage: obj._ChainAllNodes(graph_def) and returns: itertools