SynchronizedSortedSet(SortedSet<E> s) 
{
            super(s);
            ss = s;
}

 SynchronizedSortedSet(SortedSet<E> s,
    Object mutex) 
{
            super(s, mutex);
            ss = s;
}

 public Comparator<? super E> comparator() 
{
            synchronized (mutex) {return ss.comparator();}
}

 public E first() 
{
            synchronized (mutex) {return ss.first();}
}

 public SortedSet<E> headSet(E toElement) 
{
            synchronized (mutex) {
                return new SynchronizedSortedSet<  >(ss.headSet(toElement), mutex);
            }
}

 public E last() 
{
            synchronized (mutex) {return ss.last();}
}

 public SortedSet<E> subSet(E fromElement,
    E toElement) 
{
            synchronized (mutex) {
                return new SynchronizedSortedSet<  >(
                    ss.subSet(fromElement, toElement), mutex);
            }
}

 public SortedSet<E> tailSet(E fromElement) 
{
            synchronized (mutex) {
               return new SynchronizedSortedSet<  >(ss.tailSet(fromElement),mutex);
            }
}