title: extjs treepanel: expand() & expandChildNodes()
body: <p>If I write:</p>
  
  <pre><code>rootNode.expand()
  </code></pre>
  
  <p>I can only get access to the children nodes of this rootNode, but can't get access to the grandchildren nodes of this rootNode. I have to write:</p>
  
  <pre><code>rootNode.expandChildNodes()
  </code></pre>
  
  <p>in order to acheive it.</p>
  
  <p>Is there another way to obtain the grandchildren or further children nodes even if the tree is collapsed? other than using <code>node.eachChild()</code> function?
  I tried:</p>
  
  <pre><code>rootChildNode.firstChild
  </code></pre>
  
  <p>but it doesn't work.</p>