@Override
 protected void onPreExecute() {
   super.onPreExecute();
   queueCallback.onStartQuery(this);
   if (queryCallback != null) {
     queryCallback.onStartQuery(this);
   }
 }
 @Override
 protected void onPostExecute(Object result) {
   super.onPostExecute(result);
   queueCallback.onFinishQuery(this);
   if (queryCallback != null) {
     setResult(result);
     queryCallback.onFinishQuery(this);
   }
 }