@Override
    protected void onNewResultImpl(
        @Nullable CloseableReference<CloseableImage> newResult, @Status int status) {
      if (!CloseableReference.isValid(newResult)) {
        // try to propagate if the last result is invalid
        if (isLast(status)) {
          maybeNotifyOnNewResult(null, status);
        }
        // ignore if invalid
        return;
      }
      updateSourceImageRef(newResult, status);
    }
Performs postprocessing and takes care of scheduling.
imagepipeline/src/main/java/com/facebook/imagepipeline/producers/PostprocessorProducer.java