code: func parseTTLTag(tag string) (string, time.Duration, error) {
  	fullTTLTag := ""
  	ttlTag := ""
  	matches := ttlPattern0.FindStringSubmatch(tag)
  
  	if len(matches) == 0 {
  		return "", NoTTL(), nil
  	}
  
  	if len(matches) == 2 {
  		fullTTLTag = matches[0]
  		ttlTag = matches[1]
  	}
  
  	// filter out "trailing comma"
  	ttlTag = strings.TrimRight(ttlTag, " ,")
  	ttl, err := time.ParseDuration(ttlTag)
  	if err != nil {
  		return "", NoTTL(), err
  	}
  
  	if err = ValidateTTL(ttl); err != nil {
  		return "", NoTTL(), err
  	}
  
  	return fullTTLTag, ttl, nil
  }
docs: // parseTTLTag functions parses DOSA "ttl" tag