code: def _validate_no_rels(param, rels):
      
  
      if param.field in rels:
          raise InvalidQueryParams(**{
              'detail': 'The sort query param value of "%s" is not '
                        'supported. Sorting on relationships is not '
                        'currently supported' % param.raw_field,
              'links': LINK,
              'parameter': PARAM,
          })
docs: Ensure the sortable field is not on a relationship