I finally did it. I used the same code I published but it didn't work until I used backbone with version 1.1.2 (I was using 1.0.0 or similar).
var SomeModel = Backbone.Model.extend({
defaults : {
id:null,
name:'',
order:null,
isRequired:null,
}
initialize : function(options) {
if(options.listPropertyValue !== undefined) {
this.set('collectionPropertyValue', new PropertyValueCollection(options.listPropertyValue));
}
this.unset('listPropertyValue', {
silent : true
});
}
}