title: Disabling selection of a node in ExtJS tree panel if the node is not a leaf node
body: <p>I am using ExtJs 4.1 TreePanel control &amp; want to disable selection of a node if that node is not a leaf node. Do we have any property out of the box to achieve this? </p>
  
  <p>So If the node is not a leaf node, disable selection and if user click on that node, system should not fire any event (itemClick or select etc).</p>
  
  <p>Thank you</p>