code: def testGoldenPackedExtensions(self):
      golden_data = test_util.GoldenFile(
          "golden_packed_fields_message"
      ).read()
      golden_message = unittest_pb2.TestPackedExtensions()
      golden_message.ParseFromString(golden_data)
      all_set = unittest_pb2.TestPackedExtensions()
      test_util.SetAllPackedExtensions(all_set)
      self.assertEquals(all_set, golden_message)
      self.assertEqual(golden_data, all_set.SerializeToString())
      golden_copy = copy.deepcopy(golden_message)
      self.assertEqual(golden_data, golden_copy.SerializeToString())
  
imports: import copy
  import math
  import operator
  import pickle
  import unittest
  from google.protobuf import unittest_import_pb2
  from google.protobuf import unittest_pb2
  from google.protobuf.internal import api_implementation
  from google.protobuf.internal import test_util
  from google.protobuf import message
label_desc: Use image node_id 4 for calling the MessageTest obj's underlying member method code with example usage: obj.testGoldenPackedExtensions() without return types