def get_queryset(self, *args, **kwargs):
        return super(TreeManager, self).get_queryset(
            *args, **kwargs
        ).order_by(
            self.tree_id_attr, self.left_attr
        )
Ensures that this manager always returns nodes in tree order.
dataset/ETHPy150Open django-mptt/django-mptt/mptt/managers.py/TreeManager.get_queryset