def update_stale(self, now):
        with self.lock:
            for device in self.devices.values():
                if (device.track and device.last_update_home and
                        device.stale(now)):
                    device.update_ha_state(True)
Update stale devices.
dataset/ETHPy150Open home-assistant/home-assistant/homeassistant/components/device_tracker/__init__.py/DeviceTracker.update_stale