Ext.js Container Inside Container

Ext.js Container Inside Container

<!DOCTYPE html>
<html>
   <head>
      <link href = "https://cdnjs.cloudflare.com/ajax/libs/extjs/6.0.0/classic/theme-classic/resources/theme-classic-all.css"
         rel = "stylesheet" />
      <script type = "text/javascript"
         src = "https://cdnjs.cloudflare.com/ajax/libs/extjs/6.0.0/ext-all.js"></script>

      <script type = "text/javascript">
         Ext.onReady(function () {
            var component1 = Ext.create('Ext.Component', {
               html:'First Component'
            });
            var component2 = Ext.create('Ext.Component', {
               html: 'Second Component'
            });
            var component3 = Ext.create('Ext.Component', {
               html: 'Third Component'
            });
            var component4 = Ext.create('Ext.Component', {
               html: 'Fourth Component'
            });
            var container = Ext.create('Ext.container.Container', {
               style: {borderStyle: 'solid', borderWidth: '2px' },
               width: '50%',
               items: [component3, component4]
            });
            Ext.create('Ext.container.Container', {
               renderTo: Ext.getBody(),
               title: 'Container',
               border: 1,
               width: '50%',
               style: {borderStyle: 'solid', borderWidth: '2px' },
               items: [component1, component2,  container]
            });
         });
      </script>
   </head>

   <body>
   </body>
</html>