title: How to expand and collapse parts of NSSplitView programmatically?
body: <p>I want to replace <code>RBSplitView</code> with <code>NSSplitView</code> in my existing project. The application is now leopard only and I would like to replace <code>RBSplitView</code> with the <em>new</em> <code>NSSplitView</code> shipped with Leopard.</p>
  
  <p>However, I'm missing <code>RBSplitView</code>'s handy methods <code>expand</code> and <code>collapse</code> in <code>NSSplitView</code>. How can I expand and collapse parts of NSSplitView  programmatically?</p>