code: def testAssets(self):
      original_asset_file = os.path.join(
          self.get_temp_dir(), "hello.txt"
      )
      _write_string_to_file(original_asset_file, "hello world")
  
      with tf.Graph().as_default() as graph:
          asset_tensor = tf.constant(original_asset_file, name="file")
          graph.add_to_collection(
              tf.compat.v1.GraphKeys.ASSET_FILEPATHS, asset_tensor
          )
          saved_model_lib.add_signature(
              "default", {}, {"default": asset_tensor}
          )
  
      handler = saved_model_lib.SavedModelHandler()
      handler.add_graph_copy(graph)
  
      export_dir = os.path.join(self.get_temp_dir(), "exported")
      handler.export(export_dir)
  
      # Check that asset file got written to the expected place:
      exported_asset_file = os.path.join(
          export_dir, "assets", "hello.txt"
      )
      self.assertTrue(tf.compat.v1.gfile.Exists(exported_asset_file))
  
      loaded_handler = saved_model_lib.load(export_dir)
      with _instantiate_meta_graph(loaded_handler).as_default():
          with tf.compat.v1.Session() as sess:
              self.assertEqual(
                  sess.run("file:0"),
                  tf.compat.as_bytes(exported_asset_file),
              )
  
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 2 for calling the SavedModelLibTest obj's underlying member method code with example usage: obj.testAssets() without return types