code: func (r *Range) String() string {
  	switch {
  	case r.from == nil && r.to == nil:
  		return ""
  	case r.from == nil:
  		return fmt.Sprintf("-%d", *r.to)
  	case r.to == nil:
  		return fmt.Sprintf("%d-", *r.from)
  	case *r.from == *r.to:
  		return fmt.Sprintf("%d", *r.to)
  	default:
  		return fmt.Sprintf("%d-%d", *r.from, *r.to)
  	}
  }
docs: // String returns a parse-able string representation of a Range