万一有人用谷歌搜索它并从中受益，则声明了'Action'方法而没有:(id)sender参数:

In case somebody might google this out and benefit, 'Action' method was declared without :(id)sender parameter:

-(IBAction) quit;

奇怪的是，NSMenuItem中的setAction方法将其吃掉了，没有抱怨.哦，很好.

Strangely, setAction method in NSMenuItem ate it and didn't complain. Oh well.