def populate_instance(self, instance, id_map):
        if self.backref:
            for field in self.fields:
                identifier = instance._data[field.name]
                key = (field, identifier)
                if key in id_map:
                    setattr(instance, field.name, id_map[key])
        else:
            for field, attname in self.field_to_name:
                identifier = instance._data[field.to_field.name]
                key = (field, identifier)
                rel_instances = id_map.get(key, [])
                dest = '%s_prefetch' + field.related_name
                for inst in rel_instances:
                    setattr(inst, attname, instance)
                setattr(instance, dest, rel_instances)
dataset/ETHPy150Open coleifer/peewee/peewee.py/PrefetchResult.populate_instance/operator `%` -> `+`