public static byte[] stringListToUserClass(List<String> list) {
        if (list == null) { return null; }

        ByteArrayOutputStream buf = new ByteArrayOutputStream(32);
        DataOutputStream      out = new DataOutputStream(buf);

        try {
            for (String s : list) {
                byte[] bytes = DHCPPacket.stringToBytes(s);
                int    size  = bytes.length;

                if (size > 255) { size = 255; }
                out.writeByte(size);
                out.write(bytes, 0, size);
            }
            return buf.toByteArray();
        } catch (IOException e) {
            logger.log(Level.SEVERE, "Unexpected IOException", e);
            return buf.toByteArray();
        }
    }