code: def _get_op_from_signature_def(
      meta_graph_def, op_signature_key, import_scope
  ):
      """Retrieve op stored in the imported meta graph's signature def."""
      if op_signature_key in meta_graph_def.signature_def:
          return signature_def_utils.load_op_from_signature_def(
              meta_graph_def.signature_def[op_signature_key],
              op_signature_key,
              import_scope,
          )
      else:
          return None
  
imports: import os
  import sys
  from google.protobuf import message
  from google.protobuf import text_format
  from tensorflow.core.framework import graph_debug_info_pb2
  from tensorflow.core.protobuf import meta_graph_pb2
  from tensorflow.core.protobuf import saved_model_pb2
  from tensorflow.python.framework import ops
  from tensorflow.python.lib.io import file_io
  from tensorflow.python.ops import variables
  from tensorflow.python.platform import tf_logging
  from tensorflow.python.saved_model import constants
  from tensorflow.python.saved_model import path_helpers
  from tensorflow.python.saved_model import signature_def_utils
  from tensorflow.python.saved_model import utils_impl
  from tensorflow.python.saved_model.pywrap_saved_model import metrics
  from tensorflow.python.training import saver
  from tensorflow.python.util import compat
  from tensorflow.python.util import deprecation
  from tensorflow.python.util.tf_export import tf_export
label_desc: Use image node_id 6 for calling a global function with example usage: _get_op_from_signature_def(meta_graph_def, op_signature_key, import_scope) and returns: signature_def_utils, None