/** CookieList from a JSONObject with valid key and null value */
 @Test
 public void convertCookieListWithNullValueToString() {
   JSONObject jsonObject = new JSONObject();
   jsonObject.put("key", JSONObject.NULL);
   String cookieToStr = CookieList.toString(jsonObject);
   assertTrue("toString() should be empty", "".equals(cookieToStr));
 }