code: def testTags(self):
      with tf.Graph().as_default() as graph:
          saved_model_lib.add_signature(
              "default", {}, {"default": tf.constant(1)}
          )
      handler = saved_model_lib.SavedModelHandler()
      handler.add_graph_copy(graph, ["tag1"])
      handler.add_graph_copy(graph, ["tag1", "tag2"])
      self.assertAllEqual(
          sorted(handler.get_tags()),
          sorted([set(["tag1"]), set(["tag1", "tag2"])]),
      )
      self.assertIsNotNone(handler.get_meta_graph_copy(["tag1"]))
      self.assertIsNotNone(
          handler.get_meta_graph_copy(["tag2", "tag1"])
      )
      with self.assertRaises(KeyError):
          handler.get_meta_graph_copy(["tag2"])
  
imports: import copy
  import os
  from absl import logging
  import tensorflow
  from tensorflow_hub import saved_model_lib
  from tensorflow.core.protobuf import meta_graph_pb2
label_desc: Use image node_id 8 for calling the SavedModelLibTest obj's underlying member method code with example usage: obj.testTags() without return types