/** Caching user after it's retrieving. */
  @Override
  protected void onPostExecute(FbUser result) {
    super.onPostExecute(result);
    adapter.cacheUser(result);

    // recursive call of an asynchronous task
    if (position < adapter.getCount() - 1) {
      new FetchDataTask(adapter, ++position).execute();
    }
  }
 /** Get LazyAdapter to work with. */
 public FetchDataTask(LazyAdapter adapter, int position) {
   this.adapter = adapter;
   this.position = position;
   this.id = (String) adapter.getItem(position);
 }