return Iterators.pollNext(descendingIterator());
    }

    private NavigableSet<V> wrap(NavigableSet<V> wrapped) {
      return new WrappedNavigableSet(key, wrapped, (getAncestor() == null) ? this : getAncestor());
    }

    @Override
    public NavigableSet<V> descendingSet() {
      return wrap(getSortedSetDelegate().descendingSet());
    }

    @Override

      return Iterators.pollNext(descendingIterator());
    }

    private NavigableSet<V> wrap(NavigableSet<V> wrapped) {
      return new WrappedNavigableSet(key, wrapped, (getAncestor() == null) ? this : getAncestor());
    }

    @Override
    public NavigableSet<V> descendingSet() {
      return wrap(getSortedSetDelegate().descendingSet());
    }

    @Override