code: func AndString(left, right string) string {
  	leftMap := map[string][]string{}
  	rightMap := map[string][]string{}
  
  	// Ignore errors
  	json.Unmarshal([]byte(left), &leftMap)
  	json.Unmarshal([]byte(right), &rightMap)
  
  	for k, v := range rightMap {
  		existing, ok := leftMap[k]
  		if ok {
  			leftMap[k] = append(existing, v...)
  		} else {
  			leftMap[k] = v
  		}
  	}
  
  	result, _ := json.Marshal(leftMap)
  
  	return string(result)
  }
docs: // AndString returns a json list of labels by merging the two specified values (left and right) serialized as string.