Function tokenWillExpireEvent

tokenWillExpireEvent(device: Device): void
Emitted when the Device's token is about to expire. Use DeviceOptions.refreshTokenMs to set a custom warning time. Default is 10000 (10 seconds) prior to the token expiring.
Parameters
- device: Device
Returns void
Example
```
device.on('tokenWillExpire', device => {
  const token = getNewTokenViaAjax();
  device.updateToken(token);
});
```