@Override
    public KTable<Windowed<K>, Long> count() {
        return count(NamedInternal.empty());
    }
@Test
    public void shouldThrowNullPointerOnCountIfMaterializedIsNull() {
        assertThrows(NullPointerException.class, () -> windowedStream.count((Materialized<String, Long, WindowStore<Bytes, byte[]>>) null));
    }