def stop(self):

        # call superclass to stop--sets self._running
        # to False so that the 'run' loop will exit cleanly.
        BackendBase.stop(self)

        # disconnect from modem
        if self.modem != None:
            self.modem.disconnect()
dataset/ETHPy150Open rapidsms/rapidsms-core-dev/lib/rapidsms/backends/gsm.py/Backend.stop/operator `is not` -> `!=`