code: def get_queryset(self):
          
          if self.model.node_order_by:
              order_by = ['parent'] + list(self.model.node_order_by)
          else:
              order_by = ['parent', 'sib_order']
          return super(AL_NodeManager, self).get_queryset().order_by(*order_by)
docs: Sets the custom queryset as the default.