title: HtmlAgilityPack remove node (thead) not working
body: <p>Want to remove a complete thead (including th's). Why this doesn't work?
  I've tried other tags and nothing happens, result text is the same. like there were no changes.</p>
  <pre><code>&lt;table&gt;
     &lt;thead&gt;
        &lt;tr&gt;
          &lt;th&gt;Hora&lt;/th&gt;
          &lt;th&gt;Estado&lt;/th&gt;
          &lt;th&gt;Motivo&lt;/th&gt;
           &lt;th&gt;Local&lt;/th&gt;
           &lt;th&gt;Recetor&lt;/th&gt;
         &lt;/tr&gt;
       &lt;/thead&gt;
   &lt;/table&gt;
  
  </code></pre>
  <p>c# code</p>
  <pre><code>doc.LoadHtml(&quot;&lt;table&gt;&lt;thead&gt;&lt;th&gt;Hora&lt;/th&gt;&lt;th&gt;Estado&lt;/th&gt;&lt;th&gt;Motivo&lt;/th&gt;&lt;th&gt;Local&lt;/th&gt;&lt;th&gt;Recetor&lt;/th&gt;&lt;/thead&gt;&lt;/table&gt;&quot;);
  
  var nodes = doc.DocumentNode.SelectNodes(&quot;//thead&quot;).ToList();
  
  foreach (var node in nodes) {
    node.Remove();
  }
  
  txtResults.Text=doc.Text;
  </code></pre>