@Override
  public Map<PCollection<?>, ReplacementOutput> mapOutputs(
      Map<TupleTag<?>, PCollection<?>> outputs, OutputT newOutput) {
    throw new UnsupportedOperationException(message);
  }
@Test
  public void mapOutputThrows() {
    thrown.expect(UnsupportedOperationException.class);
    thrown.expectMessage(message);
    factory.mapOutputs(Collections.emptyMap(), PDone.in(pipeline));
  }