code: def test_load_identifier_not_found(self):
      nothing_matches = revived_types.deserialize(
          saved_object_graph_pb2.SavedUserObject(
              identifier="_unregistered_type",
              version=versions_pb2.VersionDef(
                  producer=1, min_consumer=1, bad_consumers=[]
              ),
          )
      )
      self.assertIs(nothing_matches, None)
  
file_path: tensorflow/tensorflow/python/saved_model/revived_types_test.py
imports: from tensorflow.core.framework import versions_pb2
  from tensorflow.core.protobuf import saved_object_graph_pb2
  from tensorflow.python.platform import test
  from tensorflow.python.saved_model import revived_types
  from tensorflow.python.trackable import autotrackable
label_desc: Use image node_id 2 for calling the RegistrationMatchingTest obj's underlying member method code with example usage: obj.test_load_identifier_not_found() without return types