title: flex expand and collapse icon in Tree control
body: <p>I am having some trouble with the flex Tree control.
  I have a control in my system and of course it is data driven.</p>
  
  <p>I have a group which shows a folder icon and that's fine but it also shows an expand icon when the item has no children.</p>
  
  <p>I don't what it to show the expand icon when the group has no children but I do want to show the folder icon, because it is different entities in my system.</p>
  
  <p>here's an example of what I'm talking about. I still want to show the folder icon, the expand Icon should be hidden in this case only for the child icon.</p>
  
  <p><img src="https://farm5.static.flickr.com/4114/4871102935_daed6e6722.jpg" alt="alt text"></p>