CollectionFeature.SERIALIZABLE,
                MapFeature.ALLOWS_NULL_VALUES,
                CollectionFeature.SUPPORTS_ITERATOR_REMOVE,
                MapFeature.GENERAL_PURPOSE)
            .named("SafeTreeMap with natural comparator")
            .createTestSuite());
    suite.addTest(
        NavigableMapTestSuiteBuilder.using(
                new TestStringSortedMapGenerator() {

                  }
                })
            .withFeatures(
                CollectionSize.ANY,
                CollectionFeature.KNOWN_ORDER,
                CollectionFeature.GENERAL_PURPOSE)
            .named("SafeTreeSet with natural comparator")
            .createTestSuite());
    suite.addTest(
        SetTestSuiteBuilder.using(
                new TestStringSetGenerator() {

    return testers;
  }

  private static Set<Feature<?>> computeEntrySetFeatures(Set<Feature<?>> features) {
    Set<Feature<?>> derivedFeatures = new HashSet<>(features);
    derivedFeatures.remove(CollectionFeature.GENERAL_PURPOSE);
    derivedFeatures.remove(CollectionFeature.SUPPORTS_ADD);
    derivedFeatures.remove(CollectionFeature.ALLOWS_NULL_VALUES);
    derivedFeatures.add(CollectionFeature.REJECTS_DUPLICATES_AT_CREATION);

    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 derivedFeatures;
  }

  private static final class MultimapGetGenerator<K, V>

                    return map;
                  }
                })
            .named("CompactHashMap")
            .withFeatures(
                CollectionSize.ANY,
                MapFeature.GENERAL_PURPOSE,
                MapFeature.ALLOWS_NULL_KEYS,
                MapFeature.ALLOWS_NULL_VALUES,
                CollectionFeature.SERIALIZABLE,
                CollectionFeature.SUPPORTS_ITERATOR_REMOVE)

  /**
   * Features supported by general-purpose collections - everything but {@link #RESTRICTS_ELEMENTS}.
   *
   * @see java.util.Collection the definition of general-purpose collections.
   */
  GENERAL_PURPOSE(SUPPORTS_ADD, SUPPORTS_REMOVE, SUPPORTS_ITERATOR_REMOVE),

  /** Features supported by collections where only removal is allowed. */
  REMOVE_OPERATIONS(SUPPORTS_REMOVE, SUPPORTS_ITERATOR_REMOVE),

  SERIALIZABLE,

    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 derivedFeatures;
  }

  private static final class MultimapGetGenerator<K, V>

                    }
                    return (Map) map;
                  }
                })
            .named("MutableClassToInstanceMap")
            .withFeatures(
                MapFeature.GENERAL_PURPOSE,
                MapFeature.RESTRICTS_KEYS,
                MapFeature.ALLOWS_NULL_VALUES,
                CollectionSize.ANY,
                CollectionFeature.SERIALIZABLE,

            .withFeatures(
                CollectionSize.ANY,
                CollectionFeature.KNOWN_ORDER,
                CollectionFeature.GENERAL_PURPOSE)
            .createTestSuite());
    suite.addTest(
        SetTestSuiteBuilder.using(
                new TestStringSetGenerator() {
                  @Override

                  }
                })
            .withFeatures(
                CollectionSize.ANY,
                CollectionFeature.KNOWN_ORDER,
                CollectionFeature.GENERAL_PURPOSE,
                CollectionFeature.SERIALIZABLE,
                CollectionFeature.ALLOWS_NULL_QUERIES,
                MultisetFeature.ENTRIES_ARE_VIEWS)
            .named("TreeMultiset, Ordering.natural")