@Test
public void test_addDefaultSecretKey()  {

    Map<String, Object> requestParams = new LinkedHashMap<>();
    Map<String, Object> dataParam = new LinkedHashMap<>();
    requestParams.put("data", dataParam);
    String jsonStr = "{\"data\": {}}";
    String jsonStrDefault = "{\"data\": {\"default\":\"default\"}}";
    when(JSONUtil.getJSON(Mockito.any())).thenReturn(jsonStrDefault);
    String actualStr = ControllerUtil.addDefaultSecretKey(jsonStr);
    assertEquals(jsonStrDefault, actualStr);
}