@Override
    public KStream<K, V> filterNot(final Predicate<? super K, ? super V> predicate) {
        return filterNot(predicate, NamedInternal.empty());
    }
@Test
    public void shouldNotAllowNullPredicateOnFilterNot() {
        final NullPointerException exception = assertThrows(
            NullPointerException.class,
            () -> testStream.filterNot(null));
        assertThat(exception.getMessage(), equalTo("predicate can't be null"));
    }