docs: public static byte[] decodeHex(final String value) {
          // if string length is odd then throw exception
          if (value.length() % 2 != 0) {
              throw new NumberFormatException("odd number of characters in hex string");
          }
  
          byte[] bytes = new byte[value.length() / 2];
          for (int i = 0; i < value.length(); i += 2) {
              bytes[i / 2] = (byte) Integer.parseInt(value.substring(i, i + 2), 16);
          }
  
          return bytes;
      }