@Override
  public <T> boolean contains(PCollectionView<T> view) {
    return sideInputs.contains(view);
  }
@Test
  public void testContains() {
    PCollection<String> pc = Pipeline.create().apply(Create.of("1"));
    PCollectionView<Iterable<String>> view1 = pc.apply(View.asIterable());
    PCollectionView<Iterable<String>> view2 = pc.apply(View.asIterable());

    // Only contains view1
    SideInputHandler sideInputHandler =
        new SideInputHandler(ImmutableList.of(view1), InMemoryStateInternals.<Void>forKey(null));

    assertTrue(sideInputHandler.contains(view1));
    assertFalse(sideInputHandler.contains(view2));
  }