code: def _mock_resolve_union_channels(self, store, channels):
      del store  # Unused.
      result = []
      for channel in channels:
          channel_key = text_format.MessageToString(
              channel, as_one_line=True
          )
          result.extend(self._channel_resolve_result[channel_key])
      return result
  
imports: from typing import Set
  from unittest import mock
  import tensorflow
  from tfx.orchestration.portable.input_resolution import exceptions
  from tfx.orchestration.portable.input_resolution import input_graph_resolver
  from tfx.orchestration.portable.input_resolution import node_inputs_resolver
  from tfx.orchestration.portable.input_resolution import partition_utils
  from tfx.orchestration.portable.input_resolution import channel_resolver
  from tfx.proto.orchestration import pipeline_pb2
  import tfx.types
  from tfx.types import channel_utils
  from tfx.utils import test_case_utils
  from google.protobuf import text_format
label_desc: Use image node_id 4 for calling the NodeInputsResolverTest obj's underlying member method code with example usage: obj._mock_resolve_union_channels(store, channels) and returns: result