code: func (d *Device) AdvertiseIBeaconData(ctx context.Context, b []byte) error {
  	if err := d.HCI.AdvertiseIBeaconData(b); err != nil {
  		return err
  	}
  	<-ctx.Done()
  	d.HCI.StopAdvertising()
  	return ctx.Err()
  }
docs: // AdvertiseIBeaconData advertise iBeacon with given manufacturer data.