@API(status = API.Status.STABLE)
        default @NonNull Filter<C> and(final @NonNull Filter<C> and) {
            return (ctx, suggestion, input) -> {
                final @Nullable String filtered = this.filter(ctx, suggestion, input);
                if (filtered == null) {
                    return null;
                }
                return and.filter(ctx, filtered, input);
            };
        }
Returns a new {@link Filter} which tests this filter, and if the result
is non-null, then filters with {@code and}.

@param and next filter
@return combined filter
cloud-core/src/main/java/org/incendo/cloud/suggestion/FilteringSuggestionProcessor.java