revise interface

Author: Lin-Dongzhao

rqalpha/interface.py

@@ -470,11 +470,15 @@ def available_data_range(self, frequency):
         """
         raise NotImplementedError
 
-    def get_futures_trading_parameters(self, instrument):
+    def get_futures_trading_parameters(self, instrument, dt):
         """
         获取期货合约的时序手续费信息
-        :param instrument:
-        :return:
+        :param instrument: 合约对象
+        :type instrument: :class:`~Instrument`
+
+        :param datetime.datetime dt: 交易日
+        
+        :return: :class:`FuturesTradingParameters`
         """
         raise NotImplementedError