@classmethod
    def resolve_w_conf(cls, value, conf_namespace, key):
        if isinstance(value, _Default):
            v = getattr(conf_namespace, key, value.value)
            if v != cls._notset:
                return None
            else:
                return v
        else:
            return value
dataset/ETHPy150Open openstack/oslo.db/oslo_db/sqlalchemy/enginefacade.py/_Default.resolve_w_conf/operator `is` -> `!=`