title: how to append node from xml document to existing xml document
body: <p>I have list of tournaments in my a.xml:  </p>
  
  <pre><code>&lt;tournaments&gt;
  
      &lt;tournament&gt;
          &lt;name&gt;a&lt;/name&gt;
      &lt;/tournament&gt;
  
      &lt;tournament&gt;
          &lt;name&gt;b&lt;/name&gt;
      &lt;/tournament&gt;
  
      &lt;tournament&gt;
          &lt;name&gt;c&lt;/name&gt;
      &lt;/tournament&gt;
  
  &lt;/tournaments&gt;
  </code></pre>
  
  <p>ad then I have one tournament in b.xml</p>
  
  <pre><code>&lt;tournament&gt;
      &lt;name&gt;d&lt;/name&gt;
  &lt;/tournament&gt;
  </code></pre>
  
  <p>How I can apend document b.xml to a.xml into as another tournament ?</p>
  
  <p>so this is what I want:</p>
  
  <pre><code>&lt;tournaments&gt;
  
      &lt;tournament&gt;
          &lt;name&gt;a&lt;/name&gt;
      &lt;/tournament&gt;
  
      &lt;tournament&gt;
          &lt;name&gt;b&lt;/name&gt;
      &lt;/tournament&gt;
  
      &lt;tournament&gt;
          &lt;name&gt;c&lt;/name&gt;
      &lt;/tournament&gt;
  
      &lt;tournament&gt;
          &lt;name&gt;d&lt;/name&gt;
      &lt;/tournament&gt;
  
  &lt;/tournaments&gt;
  </code></pre>