code: def get_queryset(self):  # DROP_WITH_DJANGO15
          
  
          args = (self.model._mptt_meta.tree_id_attr,
                  self.model._mptt_meta.left_attr)
          method = 'get_query_set' if django.VERSION < (1, 6) else 'get_queryset'
          return getattr(super(SectionManager, self), method)().order_by(*args)
docs: Use the same ordering as TreeManager