title: last element with a class name in a div
body: <p>how can i get the last div with class a in a div the id = test ?
  in this case i have to get the div with content = 1000</p>
  
  <pre><code>&lt;div id="test"&gt;
  &lt;div class="a"&gt;1&lt;/div&gt;
  ..
  ..
  &lt;div class="a&gt;1000&lt;/div&gt;
  &lt;/div&gt;
  </code></pre>