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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 _ping(self, uid, addr, port):
 """ Just say hello so that pymlgame knows that your controller is still alive. Unused controllers will be deleted after a while. This function is also used to update the address and port of the controller if it has changed. :param uid: Unique id of the controller :param addr: Address of the controller :param port: Port that the controller listens on :type uid: str :type addr: str :type port: int """

        try:
            self.controllers[uid][0] = addr
            self.controllers[uid][1] = port
            self.controllers[uid][3] = time.time()

            e = Event(uid, E_PING)
            self.queue.put_nowait(e)
        except KeyError:
            # There is no such controller, ignore the command
            pass