def filter_factory(global_conf, **local_conf):
    conf = global_conf.copy()
    conf.update(local_conf)

    def auth_filter(app):
        return Swauth(app, conf)
    return auth_filter
`dbtables.Table` overrides this.
dataset/ETHPy150Open openstack/swauth/swauth/middleware.py/filter_factory--crossover with--dataset/ETHPy150Open lsaffre/lino/lino/core/tables.py/AbstractTable.get_row_by_pk