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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 tear_down(self):
 """ Called when controller is destroyed. """

        super(ReceiverController, self).tear_down()

        self.status = None
        self.launch_failure = None
        self.app_to_launch = None
        self.app_launch_event.clear()

        self._status_listeners[:] = []