/**
 * Subject interface
 * In this interface , we can only declare top 3 function, 
 * other function we can define in an abstract class which implements
 * this interface
 */
import java.util.*;

public interface Subject {
 public abstract void attach(Observer o);
 public abstract void detach(Observer o);
 public abstract void sendNotify();

 public abstract Vector getState();
 public abstract void setState(String act, String str);
}