title: Setting value for label using ComponentQuery.query()
body: <p>I have created a Window, and added a label. Now i want to access that label using <code>query</code> and set text to that label. How am i suppose to do it ? I need to change the Text of the label (<code>firstlabel</code>) using 
  <code>Ext.ComponentQuery.query</code>. Can someone help me please ?</p>
  
  <pre><code>Ext.define('ProjectExample.view.ex.FirstWin', {
      extend: 'Ext.window.Window',
      alias : 'widget.firstW',
      items: [
              xtype: 'panel',
              title: 'First Panel',
              items: [{
                  xtype: 'label',
                  name: 'firstlabel',
                  text: 'THIS IS A LABEL'
                  }]
      ];  
      var panelArr = Ext.ComponentQuery.query('panel');
  });
  </code></pre>