if (collection instanceof NavigableSet) {
      return new WrappedNavigableSet(key, (NavigableSet<V>) collection, null);
    } else {
      return new WrappedSortedSet(key, (SortedSet<V>) collection, null);
    }
  }

  // Following Javadoc copied from Multimap and SortedSetMultimap.

  /**

      } else if (collection instanceof NavigableSet) {
        return new WrappedNavigableSet(key, (NavigableSet<V>) collection, null);
      } else if (collection instanceof SortedSet) {
        return new WrappedSortedSet(key, (SortedSet<V>) collection, null);
      } else if (collection instanceof Set) {
        return new WrappedSet(key, (Set<V>) collection);
      } else {
        return new WrappedCollection(key, collection, null);