api.get_trade() 无法读取有效数据

class TradeWatcher:
    """监听成交并写入记录与通知"""
     def __init__(self, api, notifier, trader: List[Dict[str, Any]]):
        self.api = api
        self.logger = setup_logger(__name__)
        self.notifier = notifier
        self.trader = trader
        trades_snapshot = self.api.get_trade()
        self._processed_trade_ids: Set[str] = {
            trade_id for trade_id in trades_snapshot.keys() if not trade_id.startswith("_")
        }
        self._task = self.api.create_task(self._watch_trades(trades_snapshot))
     #
     async def _watch_trades(self, trades):
        async with self.api.register_update_notify(trades) as update_chan:
            async for _ in update_chan:
                self._handle_trade_updates(trades)
     #
     def _handle_trade_updates(self, trades):
        if not trades:
            return
        oc_map = {'OPEN': 'open', 'CLOSE': 'close', 'CLOSETODAY': 'close_today'}
        for trade_id, trade in trades.items():
            print("----trade1:", dump(trade))

上面代码，在标准合约测试OK，可以打印—-trade1:
但是，标准套利合约总是无法打印。是否self.api.get_trade()接口对标准套利合约不生效？