* called more than once to add features in multiple groups.
   */
  @CanIgnoreReturnValue
  public B withFeatures(Feature<?>... features) {
    return withFeatures(asList(features));
  }

  @CanIgnoreReturnValue
  public B withFeatures(Iterable<? extends Feature<?>> features) {
    for (Feature<?> feature : features) {
      this.features.add(feature);
    }
    return self();

                    return table.rowKeySet();
                  }
                })
            .named("HashBasedTable.rowKeySet")
            .withFeatures(COLLECTION_FEATURES_REMOVE)
            .withFeatures(CollectionFeature.SUPPORTS_ITERATOR_REMOVE)
            .createTestSuite());

    suite.addTest(
        SortedSetTestSuiteBuilder.using(

                return Collections.checkedNavigableSet(innerSet, String.class);
              }
            })
        .named("checkedNavigableSet/TreeSet, natural")
        .withFeatures(
            SetFeature.GENERAL_PURPOSE,
            CollectionFeature.KNOWN_ORDER,
            CollectionFeature.SERIALIZABLE,
            CollectionFeature.FAILS_FAST_ON_CONCURRENT_MODIFICATION,

              @Override
              public List<String> create(String[] elements) {
                return emptyList();
              }
            })
        .named("emptyList")
        .withFeatures(CollectionFeature.SERIALIZABLE, CollectionSize.ZERO)
        .suppressing(suppressForEmptyList())
        .createTestSuite();
  }

  public Test testsForSingletonList() {
    return ListTestSuiteBuilder.using(

                return Collections.checkedMap(map, String.class, String.class);
              }
            })
        .named("checkedMap/HashMap")
        .withFeatures(
            MapFeature.GENERAL_PURPOSE,
            MapFeature.ALLOWS_NULL_KEYS,
            MapFeature.ALLOWS_NULL_VALUES,
            MapFeature.ALLOWS_ANY_NULL_QUERIES,

                return Collections.checkedMap(map, String.class, String.class);
              }
            })
        .named("checkedMap/HashMap")
        .withFeatures(
            MapFeature.GENERAL_PURPOSE,
            MapFeature.ALLOWS_NULL_KEYS,
            MapFeature.ALLOWS_NULL_VALUES,
            MapFeature.ALLOWS_ANY_NULL_QUERIES,

      derivedSuites.add(
          MultimapTestSuiteBuilder.using(
                  new ReserializedMultimapGenerator<K, V, M>(parentBuilder.getSubjectGenerator()))
              .withFeatures(computeReserializedMultimapFeatures(parentBuilder.getFeatures()))
              .named(parentBuilder.getName() + " reserialized")
              .suppressing(parentBuilder.getSuppressedTests())

                  protected Set<String> create(String[] elements) {
                    return union(emptySet(), emptySet());
                  }
                })
            .named("empty U empty")
            .withFeatures(CollectionSize.ZERO, CollectionFeature.ALLOWS_NULL_VALUES)
            .createTestSuite());

    suite.addTest(
        SetTestSuiteBuilder.using(
                new TestStringSetGenerator() {

              @Override
              public Set<String> create(String[] elements) {
                return emptySet();
              }
            })
        .named("emptySet")
        .withFeatures(CollectionFeature.SERIALIZABLE, CollectionSize.ZERO)
        .suppressing(suppressForEmptySet())
        .createTestSuite();
  }

  public Test testsForSingletonSet() {
    return SetTestSuiteBuilder.using(

      TestSuite suite = new TestSuite();

      suite.addTest(
          NavigableSetTestSuiteBuilder.using(new ContiguousSetGenerator())
              .named("Range.asSet")
              .withFeatures(
                  CollectionSize.ANY,
                  KNOWN_ORDER,
                  ALLOWS_NULL_QUERIES,
                  NON_STANDARD_TOSTRING,
                  RESTRICTS_ELEMENTS)