code: def _get_result_constructor(self):
          
          if not self._values_list:  # we want models
              return self.model._construct_instance
          elif self._flat_values_list:  # the user has requested flattened list (1 value per row)
              key = self._only_fields[0]
              return lambda row: row[key]
          else:
              return lambda row: [row[f] for f in self._only_fields]
docs: Returns a function that will be used to instantiate query results