code: def test_proto_to_json(self):
      json_str = proto_utils.proto_to_json(self.test_proto)
      # Checks whether original field name is kept and fields are sorted.
      self.assertEqual(
          json_str.replace(" ", "").replace("\n", ""),
          '{"double_value":0.5,"int_value":2,"string_value":"hello"}',
      )
  
file_path: tfx/tfx/utils/proto_utils_test.py
imports: import tensorflow
  from tfx.utils import proto_utils
  from tfx.utils import test_case_utils
  from tfx.utils.testdata import foo_pb2
  from google.protobuf import any_pb2
  from google.protobuf import descriptor_pb2
label_desc: Use image node_id 3 for calling the ProtoUtilsTest obj's underlying member method code with example usage: obj.test_proto_to_json() without return types