public int hashCode() {
      return standardHashCode();
    }

    @Override
    public boolean add(E element) {
      return standardAdd(element);
    }

    @Override
    public boolean addAll(Collection<? extends E> collection) {
      return standardAddAll(collection);
    }

    @Override
    public void clear() {
      standardClear();
    }

    @Override

    TestSetGenerator<E> delegate =
        (TestSetGenerator<E>) parentBuilder.getSubjectGenerator().getInnerGenerator();

    List<Feature<?>> features = new ArrayList<>();
    features.add(DESCENDING_VIEW);
    features.addAll(parentBuilder.getFeatures());

    return NavigableSetTestSuiteBuilder.using(
            new TestSetGenerator<E>() {

              @Override
              public SampleElements<E> samples() {

    }

    @Override
    public int add(@ParametricNullness E element, int occurrences) {
      throw new UnsupportedOperationException();
    }

    @Override
    public boolean addAll(Collection<? extends E> elementsToAdd) {
      throw new UnsupportedOperationException();
    }

    @Override
    public boolean remove(@CheckForNull Object element) {

    }

    @Override
    public int add(@ParametricNullness E element, int occurrences) {
      throw new UnsupportedOperationException();
    }

    @Override
    public boolean addAll(Collection<? extends E> elementsToAdd) {
      throw new UnsupportedOperationException();
    }

    @Override
    public boolean remove(@CheckForNull Object element) {

      checkArgument(predicate.apply(element));
      return unfiltered.add(element);
    }

    @Override
    public boolean addAll(Collection<? extends E> collection) {
      for (E element : collection) {
        checkArgument(predicate.apply(element));
      }
      return unfiltered.addAll(collection);
    }

    @Override
    public void clear() {
      Iterables.removeIf(unfiltered, predicate);
    }

     * @return this {@code Builder} object
     * @throws NullPointerException if {@code elements} contains a null element
     */
    @CanIgnoreReturnValue
    @Override
    public Builder<E> addAll(Iterable<? extends E> elements) {
      super.addAll(elements);
      return this;
    }

    /**
     * Adds each element of {@code elements} to the {@code ImmutableSortedSet}, ignoring duplicate

    return result;
  }

  /*
   * a "type A" unmodifiable collection freaks out proactively, even if there
   * wasn't going to be any actual work to do anyway
   */

  @Override
  public boolean addAll(Collection<? extends E> elementsToAdd) {
    throw up();
  }

  @Override
  public boolean removeAll(Collection<?> elementsToRemove) {
    throw up();
  }

  @Override

                  @Override
                  protected Set<String> create(String[] elements) {
                    NavigableSet<String> set = new SafeTreeSet<>(Ordering.natural().nullsFirst());
                    Collections.addAll(set, elements);
                    return set;
                  }

                  @Override
                  public List<String> order(List<String> insertionOrder) {

        (TestSortedMapGenerator<K, V>) parentBuilder.getSubjectGenerator().getInnerGenerator();

    List<Feature<?>> features = new ArrayList<>();
    features.add(NoRecurse.DESCENDING);
    features.addAll(parentBuilder.getFeatures());

    return subSuiteUsing(new DescendingTestMapGenerator<K, V>(delegate))
        .named(parentBuilder.getName() + " descending")
        .withFeatures(features)

                if (isNewUrl(urlQueue, urlQueueList)) {
                    targetList.add(urlQueue);
                }
            }
            urlQueueList.addAll(targetList);
        }

    }

    protected boolean isNewUrl(final UrlQueueImpl<Long> urlQueue, final Queue<UrlQueueImpl<Long>> urlQueueList) {

        final String url = urlQueue.getUrl();