def seen(self, host_name=None, location_name=None, gps=None,
             gps_accuracy=0, battery=None):
        self.last_seen = dt_util.utcnow()
        self.host_name = host_name
        self.location_name = location_name
        self.gps_accuracy = gps_accuracy or 0
        self.battery = battery
        if gps is None:
            self.gps = None
        else:
            try:
                self.gps = tuple(float(val) for val in gps)
            except ValueError:
                _LOGGER.warning('Could not parse gps value for %s: %s',
                                self.dev_id, gps)
                self.gps = None
        self.update()
Mark the device as seen.
dataset/ETHPy150Open home-assistant/home-assistant/homeassistant/components/device_tracker/__init__.py/Device.seen