protected Multiset<String> create(String[] elements) {
                    Multiset<String> ms = new NoRemoveMultiset<>();
                    Collections.addAll(ms, elements);
                    return ms;
                  }
                })
            .named("NoRemoveMultiset")
            .withFeatures(
                CollectionSize.ANY,
                CollectionFeature.ALLOWS_NULL_VALUES,