title: childNodes for documentElement returns one null
body: <p>I am performing some simple JS test for traversing and i was wondering why my documentElement consist of one null object?</p>
  
  <pre><code>&lt;html&gt;
      &lt;head&gt;
          &lt;title&gt;My document&lt;/title&gt;
      &lt;/head&gt;
      &lt;body&gt;
          &lt;h1&gt;Some header&lt;/h1&gt;
          &lt;p id="pID"&gt;Some paragraph&lt;/p&gt;
          &lt;p name="pNAME"&gt;Another paragraph/p&gt;
      &lt;/body&gt;
  &lt;/html&gt;
  &lt;script type="text/javascript"&gt;
      var rootElement = document.documentElement;
      var childNodes = rootElement.childNodes;
  
      for (var i = 0; i &lt; childNodes.length; i++) {
        document.write(childNodes[i].localName);
        document.write("&lt;br&gt;");
      }
  &lt;/script&gt;
  </code></pre>
  
  <p>It returns <code>head, null, body</code>. But why is there 3 <code>childNodes</code> in the <code>rootElement</code>?</p>