@Test
  public void testPassOnFailure() {
    setupInputProducerFailure();
    mSwallowResultProducer.produceResults(mConsumer, mProducerContext);
    verify(mConsumer).onFailure(mException);
    verifyNoMoreInteractions(mConsumer);
  }
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