public static List<String> keysByMeta(CSProperties csp, String mkey, String mval) {
        List<String> l = new ArrayList<String>();
        for (String key : csp.keySet()) {
            if (csp.getInfo(key).keySet().contains(mkey)) {
                String role = csp.getInfo(key).get(mkey);
                if (role.equals(mval)) {
                    l.add(key);
                }
            }
        }
        return l;
    }