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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 _handle_cancel_notification(self, msg_id):
 """Handle a cancel notification from the client."""

        request_future = self._client_request_futures.pop(msg_id, None)

        if not request_future:
            log.warn("Received cancel notification for unknown message id %s", msg_id)
            return

        # Will only work if the request hasn't started executing
        if request_future.cancel():
            log.debug("Cancelled request with id %s", msg_id)