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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_channel_disconnected(self):
 """ Handles a channel being disconnected. """

        for namespace in self.app_namespaces:
            if namespace in self._handlers:
                self._handlers[namespace].channel_disconnected()

        self.app_namespaces = []
        self.destination_id = None
        self.session_id = None