public class MallardDuck extends java.lang.Object implements Quackable
MallardDuck()
void
quack()
java.lang.String
toString()
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait
public MallardDuck()
public void quack()
quack
Quackable
public java.lang.String toString()
toString
java.lang.Object