code: func URLJoin(baseURL string, paths ...string) (string, error) {
  	u, err := url.Parse(baseURL)
  	if err != nil {
  		return "", err
  	}
  	// We want path instead of filepath because path always uses /.
  	all := []string{u.Path}
  	all = append(all, paths...)
  	u.Path = path.Join(all...)
  	return u.String(), nil
  }
docs: // URLJoin joins a base URL to one or more path components.
  //
  // It's like filepath.Join for URLs. If the baseURL is pathish, this will still
  // perform a join.
  //
  // If the URL is unparsable, this returns an error.