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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 stop(self):
 """Stop the gateway."""

        _LOGGER.info('Stopping gateway')
        self._disconnect()
        if self.connect_task and not self.connect_task.cancelled():
            self.connect_task.cancel()
            self.connect_task = None
        if not self.persistence:
            return
        if self._cancel_save is not None:
            self._cancel_save()
            self._cancel_save = None
        yield from self.loop.run_in_executor(
            None, self.persistence.save_sensors)