I am using NestedList code from documentation as is. Just doesn't work ! Anything wrong in following ? Shows empty when displayed. I have been trying my own code but realized this simple code also does not work.
Code:
var data = {
     text: 'Groceries',
     items: [{
         text: 'Drinks',
         items: [{
             text: 'Water',
             items: [{
                 text: 'Sparkling',
                 leaf: true
             }, {
                 text: 'Still',
                 leaf: true
             }]
         }, {
             text: 'Coffee',
             leaf: true
         }, {
             text: 'Espresso',
             leaf: true
         }, {
             text: 'Redbull',
             leaf: true
         }, {
             text: 'Coke',
             leaf: true
         }, {
             text: 'Diet Coke',
             leaf: true
         }]
     }, {
         text: 'Fruit',
         items: [{
             text: 'Bananas',
             leaf: true
         }, {
             text: 'Lemon',
             leaf: true
         }]
     }, {
         text: 'Snacks',
         items: [{
             text: 'Nuts',
             leaf: true
         }, {
             text: 'Pretzels',
             leaf: true
         }, {
             text: 'Wasabi Peas',
             leaf: true
         }]
     }]
 };


 Ext.define('ListItem', {
     extend: 'Ext.data.Model',
     fields: [{
         name: 'text',
         type: 'string'
     }]
 });


 var store = Ext.create('Ext.data.TreeStore', {
     model: 'ListItem',
     defaultRootProperty: 'items',
     root: data
 });


 var nestedList = Ext.create('Ext.NestedList', {
     fullscreen: true,
     title: 'Groceries',
     displayField: 'text',
     store: store
 });

Ext.application({
    name: 'xyz',
    phoneStartupScreen: 'images/b.jpg',
    launch: function() {


 var nestedList = Ext.create('Ext.NestedList', {
     fullscreen: true,
     title: 'Groceries',
     displayField: 'text',
     store: store      

    }
});