title: Metro Style App HttpWebRequest Headers doesn't contain a definition for Add
body: <p>I want to add custom header/value pair into HttpWebRequest object's headers collection. I can add custom header/value pair into the collection in WPF application like this.</p>
  
  <pre><code>HttpWebRequest HWR = (HttpWebRequest)WebRequest.Create("........");
  WHR.Headers.Add("Header", "Value");
  </code></pre>
  
  <p>But!</p>
  
  <p>When I use the same code in a Metro Style App, an error as title rises. How am I supposed to add custom header/value pair into headers collection?</p>
  
  <p>Thank you...</p>