postCreate for extended layout

jsonTemplate: [{dojoType: dijit.layout.ContentPane, params: {}, attachPoint: "foo"}],
postCreate: function(){
   this.inherited(arguments);
   dojo.forEach(this.jsonTemplate, this.instantiateChild, this);
}

instantiateChild: function(child){
    var w=new child.dojoType(child.params);
    this.addChild(w);

    if (child.attachPoint){
        this[child.attachPoint] = w;
    }
}