Ember-data: pushObject doesn't set parent's type and id on polymorphic association

here is an idiomatic hasMany/belongsTo polymorphic example where email can belongs to the many types of Contactable ('profile' is one of them) http://ift.tt/1G0ksCa, which is perfectly described in the http://ift.tt/1ngZypF

The problem is that after profile.get('emails').pushObject(email); email's 'contactable' and 'contactableType' are empty. This is not how it is supposed to be, right?