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