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

    value.clear();
    value.readLater();

    value.add(5);
    value.add(6);
    assertThat(value.read(), Matchers.equalTo(11));

    value.add(2);
    assertThat(value.read(), Matchers.equalTo(13));

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