public void SetUp()
        {
            _ns = TweetConverter.NS;

            _twitterXml = XDocument.Parse(
                          @"<?xml version='1.0' encoding='utf-16'?>
                            <feed xmlns:google='http://base.google.com/ns/1.0' xml:lang='en-US' xmlns:openSearch='http://a9.com/-/spec/opensearch/1.1/' xmlns='http://www.w3.org/2005/Atom' xmlns:twitter='http://api.twitter.com/'>
                              <entry>
                                <id>tag:search.twitter.com,2005:11888749530</id>
                                <published>2010-04-09T16:22:00Z</published>
                                <link type='text/html' href='http://twitter.com/lcorneliussen/statuses/11888749530' rel='alternate' />
                                <title>content from first tweet</title>
                                <updated>2010-04-09T16:22:00Z</updated>
                                <link type='image/png' href='http://twitter.com/user1.jpg' rel='image' />
                                <author>
                                  <name>first twitter user</name>
                                  <uri>http://twitter.com/user1</uri>
                                </author>
                              </entry>
                              <entry>
                                <id>tag:search.twitter.com,2005:11882613726</id>
                                <published>2010-04-09T14:15:00Z</published>
                                <link type='text/html' href='http://twitter.com/anoras/statuses/11882613726' rel='alternate' />
                                <title>content from second tweet</title>
                                <updated>2010-04-09T14:15:00Z</updated>
                                <link type='image/png' href='http://twitter.com/user2.jpg' rel='image' />
                                <author>
                                  <name>second twitter user</name>
                                  <uri>http://twitter.com/user2</uri>
                                </author>
                              </entry>
                            </feed>");

            var tweetXml = _twitterXml.Descendants(_ns + "entry").First();
            _firstTweet = TweetConverter.FromXml(tweetXml);
        }
 private void GetImage(TweetCellController controller, Tweet tweet)
 {
     controller.ImageView.Alpha = 0.0f;
     if (!string.IsNullOrEmpty(tweet.AuthorImageUrl))
     {
         if (_images.ContainsKey(tweet.AuthorImageUrl))
         {
             UIImage imageThumbnail = _images[tweet.AuthorImageUrl];
             controller.ImageView.Image = imageThumbnail;
             controller.ImageView.Alpha = 1.0f;
         }
         else
         {
             controller.AuthorImageUrl = tweet.AuthorImageUrl;
             ThreadPool.QueueUserWorkItem(RequestImage, controller);
         }
     }
 }