docs: public static String toHex(byte[] data, int length) {
          StringBuffer buffer = new StringBuffer();
  
          for (int i = 0; i != length; i++) {
              int v = data[i] & 0xff;
  
              buffer.append(DIGITS.charAt(v >> 4));
              buffer.append(DIGITS.charAt(v & 0xf));
          }
  
          return buffer.toString();
      }