code: def testMapFields(self):
      message = json_format_proto3_pb2.TestMap()
      message.bool_map[True] = 1
      message.bool_map[False] = 2
      message.int32_map[1] = 2
      message.int32_map[2] = 3
      message.int64_map[1] = 2
      message.int64_map[2] = 3
      message.uint32_map[1] = 2
      message.uint32_map[2] = 3
      message.uint64_map[1] = 2
      message.uint64_map[2] = 3
      message.string_map["1"] = 2
      message.string_map["null"] = 3
      self.assertEqual(
          json.loads(json_format.MessageToJson(message, True)),
          json.loads(
              "{"
              '"boolMap": {"false": 2, "true": 1},'
              '"int32Map": {"1": 2, "2": 3},'
              '"int64Map": {"1": 2, "2": 3},'
              '"uint32Map": {"1": 2, "2": 3},'
              '"uint64Map": {"1": 2, "2": 3},'
              '"stringMap": {"1": 2, "null": 3}'
              "}"
          ),
      )
      parsed_message = json_format_proto3_pb2.TestMap()
      self.CheckParseBack(message, 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 7 for calling the JsonFormatTest obj's underlying member method code with example usage: obj.testMapFields() without return types