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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 shutdown(self):
 """ Shutdown factory. This is shutting down all created connections and terminating ZeroMQ context. Also cleans up Twisted reactor. """

        for connection in self.connections.copy():
            connection.shutdown()

        self.connections = None

        self.context.term()
        self.context = None
        if self.trigger:
            try:
                self.reactor.removeSystemEventTrigger(self.trigger)
            except Exception:
                pass