code: func stringToList(str, delimiter string) ([]string, error) {
  	zonesSlice := make([]string, 0)
  	for _, zone := range strings.Split(str, delimiter) {
  		trimmedZone := strings.TrimSpace(zone)
  		if trimmedZone == "" {
  			return nil, fmt.Errorf(
  				"%q separated list (%q) must not contain an empty string",
  				delimiter,
  				str)
  		}
  		zonesSlice = append(zonesSlice, trimmedZone)
  	}
  	return zonesSlice, nil
  }
docs: // StringToList converts a string containing list separated by specified delimiter to a list