@Override
    public Comparator<? super E> comparator() {
      return multiset().comparator();
    }

    @Override
    public SortedSet<E> subSet(@ParametricNullness E fromElement, @ParametricNullness E toElement) {
      return multiset().subMultiset(fromElement, CLOSED, toElement, OPEN).elementSet();
    }

    @Override
    public SortedSet<E> headSet(@ParametricNullness E toElement) {

    return delegate().descendingIterator();
  }

  @Override
  public NavigableSet<E> subSet(
      @ParametricNullness E fromElement,
      boolean fromInclusive,
      @ParametricNullness E toElement,
      boolean toInclusive) {
    return delegate().subSet(fromElement, fromInclusive, toElement, toInclusive);
  }

  /**

  @Override
  public NavigableSet<E> subSet(
      E fromElement, boolean fromInclusive, E toElement, boolean toInclusive) {
    return new SafeTreeSet<>(
        delegate.subSet(
            checkValid(fromElement), fromInclusive, checkValid(toElement), toInclusive));
  }

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

  @Override

    return delegate().last();
  }

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

  @Override
  public SortedSet<E> tailSet(@ParametricNullness E fromElement) {
    return delegate().tailSet(fromElement);
  }

  /**

  public SortedMultiset<E> subMultiset(
      E fromElement, BoundType fromBoundType, E toElement, BoundType toBoundType) {
    return forwardMultiset()
        .subMultiset(toElement, toBoundType, fromElement, fromBoundType)
        .descendingMultiset();
  }

  @Override
  public SortedMultiset<E> tailMultiset(E fromElement, BoundType boundType) {
    return forwardMultiset().headMultiset(fromElement, boundType).descendingMultiset();
  }

      @ParametricNullness E fromElement,
      BoundType fromBoundType,
      @ParametricNullness E toElement,
      BoundType toBoundType) {
    return forwardMultiset()
        .subMultiset(toElement, toBoundType, fromElement, fromBoundType)
        .descendingMultiset();
  }

  @Override
  public SortedMultiset<E> tailMultiset(@ParametricNullness E fromElement, BoundType boundType) {

  }

  @Override
  ImmutableSortedSet<E> subSetImpl(
      E fromElement, boolean fromInclusive, E toElement, boolean toInclusive) {
    return forward.subSet(toElement, toInclusive, fromElement, fromInclusive).descendingSet();
  }

  @Override
  ImmutableSortedSet<E> tailSetImpl(E fromElement, boolean inclusive) {
    return forward.headSet(fromElement, inclusive).descendingSet();
  }

  @Override

  ImmutableSortedSet<E> subSetImpl(
      E fromElement, boolean fromInclusive, E toElement, boolean toInclusive) {
    return tailSetImpl(fromElement, fromInclusive).headSetImpl(toElement, toInclusive);
  }

  @Override
  ImmutableSortedSet<E> tailSetImpl(E fromElement, boolean inclusive) {
    return getSubSet(tailIndex(fromElement, inclusive), size());
  }

  int tailIndex(E fromElement, boolean inclusive) {

    }

    @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) {

      @ParametricNullness E fromElement,
      BoundType fromBoundType,
      @ParametricNullness E toElement,
      BoundType toBoundType) {
    return forwardMultiset()
        .subMultiset(toElement, toBoundType, fromElement, fromBoundType)
        .descendingMultiset();
  }

  @Override
  public SortedMultiset<E> tailMultiset(@ParametricNullness E fromElement, BoundType boundType) {