title: GetResponseAsync does not accept cancellationToken
body: <p>It seems that GetResponseAsync does not accept cancellationToken in Async/Await. So the question is how can I cancel the below procedure, provided I need to collect Cookies from response:</p>
  
  <pre><code> using (HttpWebResponse response = (HttpWebResponse) await request.GetResponseAsync())
   {
      cookies.Add(response.Cookies);
   }
  </code></pre>
  
  <p>An alternative code to achieve the above is also welcome.</p>