<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def cancelRealTimeBars(self, bars: RealTimeBarList):
 """ Cancel the realtime bars subscription. Args: bars: The bar list that was obtained from ``reqRealTimeBars``. """

        self.client.cancelRealTimeBars(bars.reqId)
        self.wrapper.endSubscription(bars)