}

  /** Throw {@link IllegalStateException} if {@link #createTestSuite()} can't be called yet. */
  protected void checkCanCreate() {
    if (subjectGenerator == null) {
      throw new IllegalStateException("Call using() before createTestSuite().");
    }
    if (name == null) {
      throw new IllegalStateException("Call named() before createTestSuite().");
    }
    if (features == null) {

                  }
                })
            .named("empty U empty")
            .withFeatures(CollectionSize.ZERO, CollectionFeature.ALLOWS_NULL_VALUES)
            .createTestSuite());

    suite.addTest(
        SetTestSuiteBuilder.using(
                new TestStringSetGenerator() {
                  @Override
                  protected Set<String> create(String[] elements) {

              }
            })
        .named("emptySet")
        .withFeatures(CollectionFeature.SERIALIZABLE, CollectionSize.ZERO)
        .suppressing(suppressForEmptySet())
        .createTestSuite();
  }

  public Test testsForSingletonSet() {
    return SetTestSuiteBuilder.using(
            new TestStringSetGenerator() {
              @Override

            CollectionSize.ANY)
        // don't skip collection tests since checkedQueue() is not tested by TestsForListsInJavaUtil
        .suppressing(suppressForCheckedQueue())
        .createTestSuite();
  }

  public Test testsForArrayDeque() {
    return QueueTestSuiteBuilder.using(
            new TestStringQueueGenerator() {
              @Override

            CollectionFeature.FAILS_FAST_ON_CONCURRENT_MODIFICATION,
            CollectionFeature.RESTRICTS_ELEMENTS,
            CollectionSize.ANY)
        .suppressing(suppressForCheckedNavigableSet())
        .createTestSuite();
  }

  public Test testsForEmptySet() {
    return SetTestSuiteBuilder.using(
            new TestStringSetGenerator() {
              @Override

                CollectionSize.SEVERAL,
                CollectionFeature.KNOWN_ORDER,
                CollectionFeature.REJECTS_DUPLICATES_AT_CREATION,
                CollectionFeature.ALLOWS_NULL_QUERIES)
            .createTestSuite());

    suite.addTest(
        SetTestSuiteBuilder.using(
                new TestStringSetGenerator() {
                  @Override
                  protected Set<String> create(String[] elements) {

                })
            .named("unmodifiableNavigableMap[SafeTreeMap]")
            .withFeatures(
                CollectionSize.ANY, MapFeature.ALLOWS_NULL_VALUES, CollectionFeature.SERIALIZABLE)
            .createTestSuite());
    suite.addTest(
        BiMapTestSuiteBuilder.using(
                new TestStringBiMapGenerator() {
                  @Override

                MapFeature.GENERAL_PURPOSE,
                MapFeature.FAILS_FAST_ON_CONCURRENT_MODIFICATION,
                CollectionFeature.SUPPORTS_ITERATOR_REMOVE,
                CollectionSize.ANY)
            .createTestSuite());

    suite.addTest(
        SetTestSuiteBuilder.using(
                new TestStringSetGenerator() {
                  @Override
                  protected Set<String> create(String[] elements) {

              }
            })
        .named("emptyList")
        .withFeatures(CollectionFeature.SERIALIZABLE, CollectionSize.ZERO)
        .suppressing(suppressForEmptyList())
        .createTestSuite();
  }

  public Test testsForSingletonList() {
    return ListTestSuiteBuilder.using(
            new TestStringListGenerator() {
              @Override

              }
            })
        .named("emptyList")
        .withFeatures(CollectionFeature.SERIALIZABLE, CollectionSize.ZERO)
        .suppressing(suppressForEmptyList())
        .createTestSuite();
  }

  public Test testsForSingletonList() {
    return ListTestSuiteBuilder.using(
            new TestStringListGenerator() {
              @Override