// the other {@code final} reference.
  @Override
  public SortedMultiset<E> descendingMultiset() {
    UnmodifiableSortedMultiset<E> result = descendingMultiset;
    if (result == null) {
      result = new UnmodifiableSortedMultiset<>(delegate().descendingMultiset());
      result.descendingMultiset = this;
      return descendingMultiset = result;
    }
    return result;
  }

  @Override

  }

  @Override
  public ImmutableSortedMultiset<E> descendingMultiset() {
    return forward;
  }

  @Override
  public ImmutableSortedMultiset<E> headMultiset(E upperBound, BoundType boundType) {
    return forward.tailMultiset(upperBound, boundType).descendingMultiset();
  }

  @Override
  public ImmutableSortedMultiset<E> tailMultiset(E lowerBound, BoundType boundType) {

  }

  @Override
  public ImmutableSortedMultiset<E> descendingMultiset() {
    return forward;
  }

  @Override
  public ImmutableSortedMultiset<E> headMultiset(E upperBound, BoundType boundType) {
    return forward.tailMultiset(upperBound, boundType).descendingMultiset();
  }

  @Override
  public ImmutableSortedMultiset<E> tailMultiset(E lowerBound, BoundType boundType) {

  /**
   * Returns a {@link SortedSet} view of the distinct elements in this multiset. (Outside GWT, this
   * returns a {@code NavigableSet}.)
   */
  @Override
  SortedSet<E> elementSet();

  SortedMultiset<E> descendingMultiset();

  SortedMultiset<E> headMultiset(E upperBound, BoundType boundType);

  SortedMultiset<E> subMultiset(
      E lowerBound, BoundType lowerBoundType, E upperBound, BoundType upperBoundType);

    protected SortedMultiset<E> delegate() {
      return backingMultiset;
    }

    @Override
    public SortedMultiset<E> descendingMultiset() {
      return new StandardDescendingMultiset() {

        @Override
        Iterator<Entry<E>> entryIterator() {
          return backingMultiset.descendingMultiset().entrySet().iterator();
        }
      };
    }

    @Override
    public NavigableSet<E> elementSet() {

  public abstract ImmutableSortedSet<E> elementSet();

  @LazyInit transient @Nullable ImmutableSortedMultiset<E> descendingMultiset;

  @Override
  public ImmutableSortedMultiset<E> descendingMultiset() {
    ImmutableSortedMultiset<E> result = descendingMultiset;
    if (result == null) {
      return descendingMultiset =
          this.isEmpty()
              ? emptyMultiset(Ordering.from(comparator()).reverse())

    protected SortedMultiset<E> delegate() {
      return backingMultiset;
    }

    @Override
    public SortedMultiset<E> descendingMultiset() {
      return new StandardDescendingMultiset() {

        @Override
        Iterator<Entry<E>> entryIterator() {
          return backingMultiset.descendingMultiset().entrySet().iterator();
        }
      };
    }

    @Override
    public NavigableSet<E> elementSet() {

      return getElementOrNull(multiset().tailMultiset(e, OPEN).firstEntry());
    }

    @Override
    public NavigableSet<E> descendingSet() {
      return new NavigableElementSet<>(multiset().descendingMultiset());
    }

    @Override
    public Iterator<E> descendingIterator() {
      return descendingSet().iterator();
    }

    @Override
    public @Nullable E pollFirst() {

      return getElementOrNull(multiset().tailMultiset(e, OPEN).firstEntry());
    }

    @Override
    public NavigableSet<E> descendingSet() {
      return new NavigableElementSet<>(multiset().descendingMultiset());
    }

    @Override
    public Iterator<E> descendingIterator() {
      return descendingSet().iterator();
    }

    @Override
    public @Nullable E pollFirst() {

   */
  @Override
  Iterator<E> iterator();

  /**
   * Returns a descending view of this multiset. Modifications made to either map will be reflected
   * in the other.
   */
  SortedMultiset<E> descendingMultiset();

  /**
   * Returns a view of this multiset restricted to the elements less than {@code upperBound},
   * optionally including {@code upperBound} itself. The returned multiset is a view of this