docs: private static String md5(byte[] buffer) {
          try {
              MessageDigest md = MessageDigest.getInstance("MD5");
              md.update(buffer);
              byte[] digest = md.digest();
              return new String(FlexBase64.encodeBytes(digest, 0, digest.length, false), StandardCharsets.US_ASCII);
          } catch (NoSuchAlgorithmException e) {
              // Should never happen
              throw new InternalError("MD5 not supported on this platform");
          }
      }