docs: public static String createErrorMessage(HttpException exception) {
      String json = tryParseAsJsonError(exception.content());
      if (json != null) {
        return json;
      }
  
      String msg = "HTTP code " + exception.code();
      if (isHtml(exception.content())) {
        return msg;
      }
  
      return msg + ": " + StringUtils.left(exception.content(), MAX_ERROR_MSG_LEN);
    }