@Override
  public SortedMultiset<E> descendingMultiset() {
    SortedMultiset<E> result = descendingMultiset;
    return (result == null) ? descendingMultiset = createDescendingMultiset() : result;
  }

  SortedMultiset<E> createDescendingMultiset() {
    @WeakOuter
    final class DescendingMultisetImpl extends DescendingMultiset<E> {
      @Override
      SortedMultiset<E> forwardMultiset() {