private String getData(String continent, String param) {
        DownloadListTask countryTask = new DownloadListTask(){
            @Override
            protected void onPostExecute(String result) {
                super.onPostExecute(result);
                showData(convertData(result));
            }
        };
        countryTask.execute(getString(R.string.baseUrl), "region", continent, param);
        return null;
    }