title: Ext.Create and this.callParent
body: <p>How can I use <code>Ext.create</code> and <code>this.callParent</code> together? If I use following code I will get errors retrieving data from an ajax store.</p>
  
  <pre><code>items: [
      { xtype: 'combo',
          initComponent: function() {
              ...
              this.callParent(arguments);
          }
      }
  ]
  </code></pre>
  
  <p>Any suggestions?</p>