title: how do I collpase and expand all tree nodes in a Kendo UI treeView based on a button click?
body: <p>This is not working:</p>
  
  <pre><code>&lt;script type="text/javascript"&gt;
              $('#btnCollapseAll').click(function()
              {
                  $('#treeview').collapseAll();
              });
  &lt;/script&gt;
  </code></pre>