def METHOD_NAME(self):
    if self.mapping.action == DataOperationType.ETL_UPSERT:
        tablename = upsert_tablename_for_obj_and_keys(
            self.mapping.sf_object, self.mapping.update_key
        )
        table = self.metadata.tables[tablename]
        return [self._make_outerjoin_for_upsert(table)]