@Override
    protected void onPostExecute(FetchUserTaskOutput output) {

      FinishedCallback callback = getFetchStatusesCallback(output.mCallbackHandle);
      if (callback != null) {
        callback.finished(output.mFetchResult, output.mUser);
        removeFetchStatusesCallback(callback);
      }

      super.onPostExecute(output);
    }
    @Override
    protected void onPostExecute(ModifyStatusesTaskOutput output) {

      FinishedCallback callback = getModifyStatusesCallback(output.mCallbackHandle);
      if (callback != null) {
        callback.finished(output.mResult.mErrorMessage == null, output.mFeed, output.mValue);
        removeModifyStatusesCallback(callback);
      }

      super.onPostExecute(output);
    }