code: func (w *wrapper) RemoveDevice(id protocol.DeviceID) (Waiter, error) {
  	w.mut.Lock()
  	defer w.mut.Unlock()
  
  	newCfg := w.cfg.Copy()
  	for i := range newCfg.Devices {
  		if newCfg.Devices[i].DeviceID == id {
  			newCfg.Devices = append(newCfg.Devices[:i], newCfg.Devices[i+1:]...)
  			return w.replaceLocked(newCfg)
  		}
  	}
  
  	return noopWaiter{}, nil
  }
docs: // RemoveDevice removes the device from the configuration