code: def testUnwrapChannelDict(self):
      instance_a = _MyArtifact()
      instance_b = _MyArtifact()
      channel_dict = {
          "id": channel.Channel(_MyArtifact).set_artifacts(
              [instance_a, instance_b]
          )
      }
      result = channel_utils.unwrap_channel_dict(channel_dict)
      self.assertDictEqual(result, {"id": [instance_a, instance_b]})
  
file_path: tfx/tfx/types/channel_utils_test.py
imports: import tensorflow
  from tfx.dsl.placeholder import placeholder
  from tfx.types import artifact
  from tfx.types import channel
  from tfx.types import channel_utils
  from tfx.types import standard_artifacts
label_desc: Use image node_id 4 for calling the ChannelUtilsTest obj's underlying member method code with example usage: obj.testUnwrapChannelDict() without return types