I have a parent model which hasMany children which belongTo the parent.

A store of children contains children instance. If I look at the store,
Code:
this.getStore('Children')
the items in the store contain the unwanted property "myapplication.model.parent_id". That was not the case before using the MVC pattern. How can I avoid that property?
Code:

myapplication.model.parent_id: 209
belongsto.PNG