title: How to append data into a Future<List<Adds>>
body: <p>I want to create a on scroll data load. currently I am getting data(ad list) from a api call as a <code>Future&lt;List&lt;Ads&gt;&gt;</code></p>
  <p>in scroll listener function I just want to append next page data list.</p>
  <p>there was a example of doing it with a list, I just want to do the same with a Future list</p>
  <pre><code>items.addAll(List.generate(42, (index) =&gt; 'Inserted $index'));
  </code></pre>