code: def testComponentSpec_WithUnionChannel(self):
      input_channel_1 = channel.Channel(type=_InputArtifact)
      input_channel_2 = channel.Channel(type=_InputArtifact)
      output_channel = channel.Channel(type=_OutputArtifact)
      spec = _BasicComponentSpec(
          folds=10,
          input=channel.union([input_channel_1, input_channel_2]),
          output=output_channel,
      )
  
      # Verify properties.
      self.assertEqual(10, spec.exec_properties["folds"])
      self.assertEqual(spec.inputs["input"].type, _InputArtifact)
      self.assertEqual(
          spec.inputs["input"].channels,
          [input_channel_1, input_channel_2],
      )
      self.assertIs(spec.outputs["output"], output_channel)
  
imports: import json
  import sys
  from typing import Dict, List
  import unittest
  import tensorflow
  from tfx.dsl.placeholder import placeholder
  from tfx.proto import example_gen_pb2
  from tfx.types import artifact
  from tfx.types import channel
  from tfx.types import component_spec
  from tfx.types.component_spec import ChannelParameter
  from tfx.types.component_spec import ComponentSpec
  from tfx.types.component_spec import ExecutionParameter
  from tfx.types.standard_artifacts import Examples
  from tfx.utils import proto_utils
  from google.protobuf import json_format
  from google.protobuf import text_format
label_desc: Use image node_id 4 for calling the ComponentSpecTest obj's underlying member method code with example usage: obj.testComponentSpec_WithUnionChannel() without return types