/**
 * A test client
 */
public class Test {
 public static void main(String[] args) {
 Subject mySub = new ConcreteSubject();
 ObserverA myObserverA = new ObserverA(mySub);
 ObserverB myObserverB = new ObserverB();
 mySub.attach(myObserverA);
 mySub.attach(myObserverB);

 mySub.setState("ADD", "One --- 1");
 mySub.setState("ADD", "Tow --- 2");
 mySub.sendNotify();

 myObserverA.change("DEL", "Tow --- 2");
 myObserverA.change("ADD", "Three --- 3");
 myObserverA.change("ADD", "Four --- 4");
 myObserverA.notifySub(); 
 }
}