Ext.override in EXTJs 4.x

Many times we override the behavior of the base EXTjs classes. With the earlier version of EXTjs, we did that using Ext.override. ExtJs 4 onwards the preferred way to achieve the same is using the Ext.define.

Ex: Ext.define('Override.view.Table',{
override:'Ext.view.Table',
.
.
.
});