Fill id2obj_user with all parent/relationship key item IDs and their objects.

def fill_parentidid2obj_r1(self, id2obj_user, child_obj):
        """Fill id2obj_user with all parent/relationship key item IDs and their objects."""
        for higher_obj in self._getobjs_higher(child_obj):
            if higher_obj.item_id not in id2obj_user:
                id2obj_user[higher_obj.item_id] = higher_obj
                self.fill_parentidid2obj_r1(id2obj_user, higher_obj)