import java.util.TreeSet;

/*
 * Example of isEmpty() method.
 */
public class TreeSetExample
{
    public static void main( String[] args )
    {

        TreeSet<Integer> treeSet = new TreeSet<Integer>();
        
        System.out.println("treeSet : " + treeSet + "\n");
        
        /*
         * Returns true if this set contains no elements.
         */
        boolean isEmpty = treeSet.isEmpty();
        System.out.println("isEmpty :  " + isEmpty + "\n");


        treeSet.add(10);
        treeSet.add(50);
        treeSet.add(40);
        treeSet.add(20);
        treeSet.add(30);

        System.out.println("treeSet : " + treeSet + "\n");

        /*
         * Returns true if this set contains no elements.
         */
        isEmpty = treeSet.isEmpty();
        System.out.println("isEmpty :  " + isEmpty);
    }
}