public String getParamValue(String configKey, String paramKey) {

        if (key.equalsIgnoreCase(configKey)) {//search own
            for (Param param : params) {
                String ret = param.get(paramKey);
                if (ret != null) {
                    return ret;
                }
            }
        } else {//search in tree
            if (configs != null) {
                for (Config cfg : configs) {
                    String ret = cfg.getParamValue(configKey, paramKey);
                    if (ret != null) {
                        return ret;
                    }
                }
            }
        }

        return null;
    }