code: private void digestInteger(MessageDigest digest, int value) {
          byte[] valueBytes = new byte[4];
          Util.numberToBytes(value, valueBytes, 0, 4);
          digest.update(valueBytes);
      }
docs: Helper method to add a Java integer value to a message digest.
  
  @param digest the message digest being built
  @param value the integer whose bytes should be included in the digest