title: convert json to xml and save result to a file
body: <p>I'm converting a JSON string to an XML node like this:</p>
  
  <pre><code>public ActionResult Test(string json)
  { 
      System.Xml.XmlNode myXmlNode = JsonConvert.DeserializeXmlNode("{\"root\":" + json + "}", "root");  
  </code></pre>
  
  <p>How can I save myXmlNode  to an external file, say test.xml? 
  Thanks</p>