import java.util.TreeSet;
public class Main {
public static void main(String[] args) {
TreeSet tSet = new TreeSet();
tSet.add(new Integer("1"));
tSet.add(new Integer("2"));
tSet.add(new Integer("3"));
System.out.println("TreeSet before removal : " + tSet);
tSet.clear();
System.out.println("TreeSet after removal : " + tSet);
System.out.println("Is TreeSet empty ? " + tSet.isEmpty());
}
}