title: Kendo TreeView making request on expand but not showing returned data
body: <p>I have a Kendo TreeView control that will load the first level of nodes, but when I attempt to expand one the expand triangle disappears. I can see that the ajax call is being made and returning valid Json as noted below, any ideas?</p>
  
  <p>Here's the TreeView setup,</p>
  
  <pre><code>this.dataSource = new kendo.data.HierarchicalDataSource({
      transport: {
          read: {
              url: "...",
              dataType: 'json'
          }
      },
  });
  
  this.treeview = $(this.settings.selector).kendoTreeView({
      dataSource: this.dataSource,
  }).data("kendoTreeView");
  </code></pre>
  
  <p>And the Initial returned Json,</p>
  
  <pre><code>[{"id":"00000000-0000-0000-0000-000000000000","text":"Root Node","hasChildren":true,"spriteCssClass":"folder"}]
  </code></pre>
  
  <p>And finally the Json returned on node expansion,</p>
  
  <pre><code>[{"id":"8295b0c3-8f85-4c2d-8fc6-fe43be8a734b","text":"Folder A","hasChildren":false,"spriteCssClass":"folder"}]
  </code></pre>