mootools setOptions 发生too much recursion问题

 两个很简单的类

Container = new Class({
    Implements: [Events, Options],
    layout: null,
    initialize: function(options){
        this.setOptions(options);
    },
    setLayout: function(l){
        this.layout = l;
        this.layout.setContainer(this);
    }
});

Layout = new Class({
    Implements: [Events, Options],
    options: {
        item: null
    },
    container: null,
    initialize: function(o){
        this.setOptions(o);
    },
    setContainer: function(c){
        this.container = c;
    }
});

window.addEvent('domready', function(){
    var innerContainer = new Container();
    
    innerContainer.setLayout(new Layout());
    
    var container = new Container();
    var layout = new Layout({
        item: innerContainer
    });
});

执行的时候出现了：too much recursion
跟踪代码发现setOption方法会调用$unlink()方法，其中有递归代码：
for (var p in object) unlinked[p] = $unlink(object[p]);进行深度copy，把参数复制到options中。

而这段代码中Container和Layout是双向关联的。
container.setLayout()时又会把layout赋给container，而
this.layout.setContainer(this)又会把container赋给layout，所以就会出现递归调用而出错了