@Before
  public void setUp() {
    MockitoAnnotations.initMocks(this);
    mSwallowResultProducer =
        new SwallowResultProducer<CloseableReference<CloseableImage>>(mInputProducer);
    mFinalImageReference = CloseableReference.of(mock(CloseableImage.class));
    mIntermediateImageReference = CloseableReference.of(mock(CloseableImage.class));
  }
Checks basic properties of swallow result producer, that is: - it swallows all results. - it
notifies previous consumer of last result. - it notifies previous consumer of a failure.
imagepipeline/src/test/java/com/facebook/imagepipeline/producers/SwallowResultProducerTest.java