MapFeature.RESTRICTS_KEYS,
            MapFeature.SUPPORTS_REMOVE,
            CollectionFeature.FAILS_FAST_ON_CONCURRENT_MODIFICATION,
            CollectionFeature.SERIALIZABLE,
            CollectionFeature.SUPPORTS_ITERATOR_REMOVE,
            CollectionFeature.SUPPORTS_REMOVE,
            CollectionSize.ANY)
        .named("Hashtable")
        .suppressing(suppressForHashtable())

    if (derivedFeatures.contains(CollectionFeature.SUPPORTS_ADD)) {
      derivedFeatures.add(ListFeature.SUPPORTS_ADD_WITH_INDEX);
    }
    if (derivedFeatures.contains(CollectionFeature.SUPPORTS_REMOVE)) {
      derivedFeatures.add(ListFeature.SUPPORTS_REMOVE_WITH_INDEX);
    }
    if (derivedFeatures.contains(CollectionFeature.GENERAL_PURPOSE)) {
      derivedFeatures.add(ListFeature.GENERAL_PURPOSE);
    }

                    }
                    return (Map) map;
                  }
                })
            .named("MutableTypeToInstanceMap")
            .withFeatures(
                MapFeature.SUPPORTS_REMOVE,
                MapFeature.RESTRICTS_KEYS,
                MapFeature.ALLOWS_NULL_VALUES,
                CollectionFeature.SUPPORTS_ITERATOR_REMOVE,
                CollectionSize.ANY,

                CollectionSize.ANY,
                CollectionFeature.ALLOWS_NULL_VALUES,
                CollectionFeature.KNOWN_ORDER,
                CollectionFeature.SUPPORTS_ADD,
                CollectionFeature.SUPPORTS_REMOVE)
            .named("Multiset.filter[Multiset, Predicate]")
            .createTestSuite());

    return suite;
  }

  private static TestStringMultisetGenerator unmodifiableMultisetGenerator() {

    }

    @Override
    public int previousIndex() {
      return nextIndex() - 1;
    }

    @Override
    public void remove() {
      throwIfInvalid(IteratorFeature.SUPPORTS_REMOVE);

      stackWithLastReturnedElementAtTop.pop();
      stackWithLastReturnedElementAtTop = null;
    }

    @Override
    public void set(E e) {
      throwIfInvalid(IteratorFeature.SUPPORTS_SET);

                CollectionSize.ANY,
                CollectionFeature.ALLOWS_NULL_VALUES,
                CollectionFeature.KNOWN_ORDER,
                CollectionFeature.SUPPORTS_ADD,
                CollectionFeature.SUPPORTS_REMOVE)
            .named("Multiset.filter[Multiset, Predicate]")
            .createTestSuite());

    return suite;
  }

  private static TestStringMultisetGenerator unmodifiableMultisetGenerator() {

    if (derivedFeatures.contains(CollectionFeature.SUPPORTS_ADD)) {
      derivedFeatures.add(ListFeature.SUPPORTS_ADD_WITH_INDEX);
    }
    if (derivedFeatures.contains(CollectionFeature.SUPPORTS_REMOVE)) {
      derivedFeatures.add(ListFeature.SUPPORTS_REMOVE_WITH_INDEX);
    }
    if (derivedFeatures.contains(CollectionFeature.GENERAL_PURPOSE)) {
      derivedFeatures.add(ListFeature.GENERAL_PURPOSE);
    }

            MapFeature.RESTRICTS_KEYS,
            MapFeature.SUPPORTS_REMOVE,
            CollectionFeature.FAILS_FAST_ON_CONCURRENT_MODIFICATION,
            CollectionFeature.SERIALIZABLE,
            CollectionFeature.SUPPORTS_ITERATOR_REMOVE,
            CollectionFeature.SUPPORTS_REMOVE,
            CollectionSize.ANY)
        .named("Hashtable")
        .suppressing(suppressForHashtable())

              }
            })
        .named("CopyOnWriteArraySet")
        .withFeatures(
            CollectionFeature.SUPPORTS_ADD,
            CollectionFeature.SUPPORTS_REMOVE,
            CollectionFeature.SERIALIZABLE,
            CollectionFeature.ALLOWS_NULL_VALUES,
            CollectionFeature.KNOWN_ORDER,
            CollectionSize.ANY)

            ListFeature.SUPPORTS_ADD_WITH_INDEX,
            ListFeature.SUPPORTS_REMOVE_WITH_INDEX,
            ListFeature.SUPPORTS_SET,
            CollectionFeature.SUPPORTS_ADD,
            CollectionFeature.SUPPORTS_REMOVE,
            CollectionFeature.SERIALIZABLE,
            CollectionFeature.ALLOWS_NULL_VALUES,
            CollectionSize.ANY)
        .suppressing(suppressForCopyOnWriteArrayList())
        .createTestSuite();