code: def testInvalidOneof(self):
      message = json_format_proto3_pb2.TestOneof()
      text = '{"oneofInt32Value": 1, "oneofStringValue": "2"}'
      self.assertRaisesRegexp(
          json_format.ParseError,
          'Message type "proto3.TestOneof"'
          ' should not have multiple "oneof_value" oneof fields.',
          json_format.Parse,
          text,
          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 32 for calling the JsonFormatTest obj's underlying member method code with example usage: obj.testInvalidOneof() without return types