@Override
  public <T extends State> T state(StateNamespace namespace, StateTag<T> address) {
    return workItemState.get(namespace, address, StateContexts.nullContext());
  }
@Test
  public void testNewCombiningNoFetch() throws Exception {
    GroupingState<Integer, Integer> value = underTestNewKey.state(NAMESPACE, COMBINING_ADDR);

    assertThat(value.isEmpty().read(), Matchers.is(true));
    assertThat(value.read(), Matchers.is(Sum.ofIntegers().identity()));
    assertThat(value.isEmpty().read(), Matchers.is(false));

    // Shouldn't need to read from windmill for this.
    Mockito.verifyZeroInteractions(mockReader);
  }