code: func DefaultIP() string {
  	addrs, err := netInterfaceAddrs()
  	if err == nil {
  		for _, addr := range addrs {
  			if ip, ok := addr.(*net.IPNet); ok && !ip.IP.IsLoopback() {
  				if ip.IP.To4() != nil {
  					return ip.IP.String()
  				}
  			}
  		}
  	}
  
  	return ""
  }
docs: // DefaultIP is used by default when responding to a Set_Option broadcastIP request
  // It can be overridden with the Service.PrimaryIP field