package headfirst.combining.observer;public class DuckFactory extends AbstractDuckFactory {  	public Quackable createMallardDuck() {		return new MallardDuck();	}  	public Quackable createRedheadDuck() {		return new RedheadDuck();	}  	public Quackable createDuckCall() {		return new DuckCall();	}   	public Quackable createRubberDuck() {		return new RubberDuck();	}}