code: func SplitHostPort(hostname string) (string, string, error) {
  	host, port, err := net.SplitHostPort(hostname)
  	if err != nil {
  		return "", "", trace.Wrap(err)
  	}
  	if host == "" {
  		return "", "", trace.BadParameter("empty hostname")
  	}
  	return host, port, nil
  }
docs: // SplitHostPort splits host and port and checks that host is not empty