code: def _to_instances(self, pks):
          
          # we want instances, so create an object for each pk, without
          # checking for pk existence if asked
          meth = self.cls.lazy_connect if self._instances_skip_exist_test else self.cls
          return [meth(pk) for pk in pks]
docs: Returns a list of instances for each given pk, respecting the condition
          about checking or not if a pk exists.