package devopsdistilled.operp.client.abstracts;

public interface Model<O extends Observer> {
	public void registerObserver(O observer);

	public void removeObserver(O observer);

	public void notifyObservers();
}

package devopsdistilled.operp.client.abstracts;

public interface Model<O extends Observer> {
	public void registerObserver(O observer);

	public void removeObserver(O observer);

	public void notifyObservers();

	public void update();
}

Add method update() which is to be called after registerObserver()
Add method update() which is to be called after registerObserver()