code: func splitPort(port string) (local, remote string) {
  	parts := strings.Split(port, ":")
  	if len(parts) == 2 {
  		return parts[0], parts[1]
  	}
  
  	return parts[0], parts[0]
  }
docs: // splitPort splits port string which is in form of [LOCAL PORT]:REMOTE PORT
  // and returns local and remote ports separately