code: func fastURLPathEncode(path string) string {
  	for _, r := range []byte(path) {
  		switch {
  		case r >= '-' && r <= '9', r >= 'A' && r <= 'Z', r >= 'a' && r <= 'z':
  			// characters within this range do not require escaping
  		default:
  			var u url.URL
  			u.Path = path
  			return u.EscapedPath()
  		}
  	}
  	return path
  }
docs: // fastURLPathEncode encodes the provided path as a URL path