title: Html agility pack not loading url
body: <p>I have something like this:</p>
  
  <pre><code>class MyTask
  {
      public MyTask(int id)
      {
          Id = id;
          IsBusy = false;
          Document = new HtmlDocument();
      }
  
      public HtmlDocument Document { get; set; }
      public int Id { get; set; }
      public bool IsBusy { get; set; }
  }
  
  class Program
  {
      public static void Main()
      {
          var task = new MyTask(1);
          task.Document.LoadHtml("http://urltomysite");
          if (task.Document.DocumentNode.SelectNodes("//span[@class='some-class']").Count == 0)
          {
              task.IsBusy = false;
              return;
          }   
      }
  }
  </code></pre>
  
  <p>Now when I start my program, it throws an error on the <code>if</code> sttement, saying that <code>Object reference not set to an instance of an object.</code>. Why isn't it loading my page? What am I doing wrong here?</p>