@Override
    public KTable<Windowed<K>, V> reduce(final Reducer<V> reducer) {
        return reduce(reducer, NamedInternal.empty());
    }
@Test
    public void shouldThrowNullPointerOnMaterializedReduceIfNamedIsNull() {
        assertThrows(NullPointerException.class, () -> windowedStream.reduce(MockReducer.STRING_ADDER, (Named) null));
    }