code: static String byteAsChar(byte v) {
      int chr = v & 0xff;
      return String.format(Locale.ROOT, 
          "%s (0x%02x)",
          (Character.isWhitespace(chr) || chr > 127) ? "[non-printable]" : Character.toString((char) chr),
          v & 0xFF);
    }
docs: Convert a byte to an informative string.