}

    @Override
    public String toString() {
      return standardToString();
    }

    @Override
    public SortedSet<T> subSet(T fromElement, T toElement) {
      return standardSubSet(fromElement, toElement);
    }
  }

  @AndroidIncompatible // test-suite builders
  public static Test suite() {
    TestSuite suite = new TestSuite();

    }

    @Override
    public String toString() {
      return standardToString();
    }

    @Override
    public SortedSet<T> subSet(T fromElement, T toElement) {
      return standardSubSet(fromElement, toElement);
    }

    @Override
    public @Nullable T lower(T e) {
      return standardLower(e);
    }

    @Override
    public @Nullable T floor(T e) {

    }

    @Override
    public SortedSet<E> subSet(@ParametricNullness E fromElement, @ParametricNullness E toElement) {
      return standardSubSet(fromElement, toElement);
    }

    @Override
    public NavigableSet<E> headSet(@ParametricNullness E toElement, boolean inclusive) {
      return forward.tailSet(toElement, inclusive).descendingSet();

    }

    @Override
    public SortedSet<E> subSet(@ParametricNullness E fromElement, @ParametricNullness E toElement) {
      return standardSubSet(fromElement, toElement);
    }

    @Override
    public NavigableSet<E> headSet(@ParametricNullness E toElement, boolean inclusive) {
      return forward.tailSet(toElement, inclusive).descendingSet();