code: def _trace_preprocessing_fn_v1(preprocessing_fn, specs):
      """Trace TF1 graph for `preprocessing_fn`."""
      with tf.compat.v1.Graph().as_default() as graph:
          with tf.compat.v1.name_scope("inputs"):
              structured_inputs = batched_placeholders_from_specs(specs)
              # In order to avoid a bug where import_graph_def fails when the
              # input_map and return_elements of an imported graph are the same
              # (b/34288791), we avoid using the placeholder of an input column as an
              # output of a graph. We do this by applying tf.identity to all inputs of
              # the preprocessing_fn.  Note this applies at the level of raw tensors.
              # TODO(b/34288791): Remove this workaround and use a shallow copy of
              # inputs instead.  A shallow copy is needed in case
              # self._preprocessing_fn mutates its input.
              copied_inputs = tf_utils.copy_tensors(structured_inputs)
  
          structured_outputs = preprocessing_fn(copied_inputs)
      return graph, structured_inputs, structured_outputs
  
imports: import functools
  import os
  import re
  from typing import Callable, Dict, List, Mapping, Optional, FrozenSet
  from absl import logging
  import numpy
  import pyarrow
  import tensorflow
  from tensorflow_transform import analyzer_nodes
  from tensorflow_transform import annotators
  from tensorflow_transform import common_types
  from tensorflow_transform import graph_context
  from tensorflow_transform import graph_tools
  from tensorflow_transform import schema_inference
  from tensorflow_transform import tf2_utils
  from tensorflow_transform import tf_utils
  from tensorflow_transform.output_wrapper import TFTransformOutput
  from tensorflow_transform.saved import saved_transform_io
  from tensorflow_transform.saved import saved_transform_io_v2
  from tensorflow_transform.tf_metadata import dataset_metadata
  from tensorflow_transform.tf_metadata import metadata_io
  from tensorflow_transform.tf_metadata import schema_utils
  from tfx_bsl.coders import example_coder
  from tfx_bsl.tfxio import tensor_to_arrow
  from tensorflow.python.eager import function
  from tensorflow.python.framework import ops
  from tensorflow_metadata.proto.v0 import schema_pb2
label_desc: Use image node_id 12 for calling a global function with example usage: _trace_preprocessing_fn_v1(preprocessing_fn, specs) and returns: graph,  structured_inputs,  structured_outputs