docs: public static String genWithAmple(String... arr) throws NoSuchAlgorithmException {
      Arrays.sort(arr);
      StringBuilder sb = new StringBuilder();
      for (int i = 0; i < arr.length; i++) {
        String a = arr[i];
        sb.append(a);
        if (i != arr.length - 1) {
          sb.append('&');
        }
      }
      return DigestUtils.sha1Hex(sb.toString());
    }