code: func parseOptions(tag string) map[string]string {
  	parts := strings.Split(tag, ",")
  	options := make(map[string]string, len(parts))
  	if len(parts) > 1 {
  		for _, opt := range parts[1:] {
  			// short circuit potentially expensive split op
  			if strings.Contains(opt, "=") {
  				kv := strings.Split(opt, "=")
  				options[kv[0]] = kv[1]
  				continue
  			}
  			options[opt] = ""
  		}
  	}
  	return options
  }
docs: // parseOptions parses options out of a tag string, skipping the name