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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 client_disconnect(self, event):
 """ A client has disconnected, update possible subscriptions accordingly. :param event: """

        self.log("Removing disconnected client from subscriptions", lvl=debug)
        client_uuid = event.clientuuid
        self._unsubscribe(client_uuid)