pure interface of class java.util.TreeSet<A>

public class TreeSet<A>
  extends AbstractSet<A>
  implements SortedSet<A>, Cloneable, java.io.Serializable
{
    public TreeSet();
    public TreeSet(Comparator<A> c);
    public TreeSet(Collection<A> c);
    public TreeSet(SortedSet<A> s);
    public Iterator<A> iterator();
    public int size();
    public boolean isEmpty();
    public boolean contains(A o);
    public boolean add(A o);
    public boolean remove(A o);
    public void clear();
    public SortedSet<A> subSet(A fromElement,
                               A toElement);
    public SortedSet<A> headSet(A toElement);
    public SortedSet<A> tailSet(A fromElement);
    public Comparator<A> comparator();
    public A first();
    public A last();
    public Object clone();
}