code: func ToExpression(p Path, this uuid.UUID) string {
  	converted := strings.Replace(this.String(), "-", "_", -1)
  	existingPath := p.Convert()
  	if existingPath == "" {
  		return converted
  	}
  	return fmt.Sprintf("%s.%s", p.Convert(), converted)
  }
docs: // ToExpression returns a string in ltree format.
  // Joins UUIDs in the first argument using `.`
  // Second argument is converted and appended if needed