ImmutableAggregatingState extends ImmutableState implements AggregatingState<IN, OUT> { @Override public void clear() { throw MODIFICATION_ATTEMPT_ERROR; } private  ImmutableAggregatingState(OUT value); @Override OUT get(); @Override void add(Object newValue); @Override void clear(); static ImmutableAggregatingState<IN, OUT> createState(
			final AggregatingStateDescriptor<IN, ACC, OUT> stateDescriptor,
			final byte[] serializedValue);  }
@Test(expected = UnsupportedOperationException.class) public void testClear() { String value = aggrState.get(); assertEquals("42", value); aggrState.clear(); }