@Test
  public void testGetters() {
    assertEquals(mImageRequest, mSettableProducerContext.getImageRequest());
    assertEquals(mRequestId, mSettableProducerContext.getId());
  }
Checks basic properties of NullProducer, that is that it always returns null.
imagepipeline/src/test/java/com/facebook/imagepipeline/producers/SettableProducerContextTest.java