code: def testParseNull(self):
      message = json_format_proto3_pb2.TestMessage()
      parsed_message = json_format_proto3_pb2.TestMessage()
      self.FillAllFields(parsed_message)
      json_format.Parse(
          '{"int32Value": null, '
          '"int64Value": null, '
          '"uint32Value": null,'
          '"uint64Value": null,'
          '"floatValue": null,'
          '"doubleValue": null,'
          '"boolValue": null,'
          '"stringValue": null,'
          '"bytesValue": null,'
          '"messageValue": null,'
          '"enumValue": null,'
          '"repeatedInt32Value": null,'
          '"repeatedInt64Value": null,'
          '"repeatedUint32Value": null,'
          '"repeatedUint64Value": null,'
          '"repeatedFloatValue": null,'
          '"repeatedDoubleValue": null,'
          '"repeatedBoolValue": null,'
          '"repeatedStringValue": null,'
          '"repeatedBytesValue": null,'
          '"repeatedMessageValue": null,'
          '"repeatedEnumValue": null'
          "}",
          parsed_message,
      )
      self.assertEqual(message, parsed_message)
      # Null and {} should have different behavior for sub message.
      self.assertFalse(parsed_message.HasField("message_value"))
      json_format.Parse('{"messageValue": {}}', parsed_message)
      self.assertTrue(parsed_message.HasField("message_value"))
      # Null is not allowed to be used as an element in repeated field.
      self.assertRaisesRegexp(
          json_format.ParseError,
          "Failed to parse repeatedInt32Value field: "
          "null is not allowed to be used as an element in a repeated field.",
          json_format.Parse,
          '{"repeatedInt32Value":[1, null]}',
          parsed_message,
      )
  
imports: import json
  import math
  import sys
  from google.protobuf import any_pb2
  from google.protobuf import duration_pb2
  from google.protobuf import field_mask_pb2
  from google.protobuf import struct_pb2
  from google.protobuf import timestamp_pb2
  from google.protobuf import wrappers_pb2
  from google.protobuf.internal import well_known_types
  from google.protobuf import json_format
  from google.protobuf.util import json_format_proto3_pb2
label_desc: Use image node_id 19 for calling the JsonFormatTest obj's underlying member method code with example usage: obj.testParseNull() without return types