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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _cancel(self, msgId):
 """ Cancel outstanding REQ, drop reply silently. @param msgId: message ID to cancel @type msgId: C{str} """

        _, canceller = self._requests.pop(msgId, (None, None))

        if canceller is not None and canceller.active():
            canceller.cancel()