class PropertiesDecoder {

    public static Map<String,String> unflatten(final String s) {
        if(!ok(s))
            return Collections.emptyMap();

        Map<String,String> map = new HashMap<String,String>();
        String[] elements = s.split(":");

        for(String element : elements) {
            addPair(map, element);
        }

        return map;
    }

}