It seems that turing.oo.js don't support for multi inheritance??

[imnemo]

var User = turing.Class({
'initialize' : function(name, age){
console.log('User init!');
this.name = name;
this.age = age;
},
'toString' : function(){
var str = '';
for(var key in this){
if(typeof this[key] !== 'function' && key !== '$parent'){
str += key + " : " + this[key] + "\n";
}
}
return str;
}
});
var superUser = turing.Class(User, {
'initialize' : function(){
console.log('superUser init!');
this.$super('initialize', arguments);
this.sex = arguments[2];
},
'toString' : function(){
return "Overwrite the parent method : \n" + this.$super('toString');
}
});

var superSuperUser = turing.Class(superUser, {
'initialize' : function(){
console.log('superSuperUser init!');
this.$super('initialize', arguments);
this.love = arguments[3];
},
'toString' : function(){
return "Overwrite the parent method : \n" + this.$super('toString');
}
});

As shown above, superUser inherits from User and superSuperUser attempts to inherit from superUser. However, when the superSuperUser is initialized, a infinit circle happens in superUser's 'initialize' method. It seems that in superUser's 'initialize' method, "this" also points to superSuperUser, but not superUser, which case cause the infinit circle.

I just don't know if I understand something wrong, thanks anyone who can help me!