@Test
  public void testInputProducerFailure() {
    setupInputProducerFailure();
    mDiskCacheWriteProducer.produceResults(mConsumer, mProducerContext);
    verify(mConsumer).onFailure(mException);
    verifyZeroInteractions(
        mProducerListener, mDefaultBufferedDiskCache, mSmallImageBufferedDiskCache);
  }
Checks basic properties of disk cache producer operation, that is: - it delegates to the {@link
BufferedDiskCache#get(CacheKey key, AtomicBoolean isCancelled)} - it returns a 'copy' of the
cached value - if {@link BufferedDiskCache#get(CacheKey key, AtomicBoolean isCancelled)} is
unsuccessful, then it passes the request to the next producer in the sequence. - if the next
producer returns the value, then it is put into the disk cache.
imagepipeline/src/test/java/com/facebook/imagepipeline/producers/DiskCacheWriteProducerTest.java