code: func (n PidMode) Valid() bool {
  	parts := strings.Split(string(n), ":")
  	switch mode := parts[0]; mode {
  	case "", "host":
  	case "container":
  		if len(parts) != 2 || parts[1] == "" {
  			return false
  		}
  	default:
  		return false
  	}
  	return true
  }
docs: // Valid indicates whether the pid namespace is valid.