code: def testJsonRoundTripUnknownArtifactClass(self):
      chnl = channel.Channel(type=_MyType)
  
      serialized = chnl.to_json_dict()
      serialized["type"]["name"] = "UnknownTypeName"
  
      rehydrated = channel.Channel.from_json_dict(serialized)
      self.assertEqual("UnknownTypeName", rehydrated.type_name)
      self.assertEqual(
          chnl.type._get_artifact_type().properties,
          rehydrated.type._get_artifact_type().properties,
      )
      self.assertTrue(rehydrated.type._AUTOGENERATED)
  
imports: from unittest import mock
  import tensorflow
  from tfx.dsl.input_resolution import resolver_op
  from tfx.dsl.placeholder import placeholder
  from tfx.types import artifact
  from tfx.types import channel
  from tfx.types import resolved_channel
  from google.protobuf import struct_pb2
  from ml_metadata.proto import metadata_store_pb2
label_desc: Use image node_id 5 for calling the ChannelTest obj's underlying member method code with example usage: obj.testJsonRoundTripUnknownArtifactClass() without return types