Ext js override init component function

I am trying to override some code in the initComponent function of the Ext.window.MessageBox class. But none of the things that I change get applied. What is the problem here? Am I missing something?

Code:

  Ext.define('hds.override.MessageBox', {     override: 'Ext.window.MessageBox',     initComponent: function() {      console.log("init component 1"); //not reached      this.callParent();       console.log("init component 2"); //not reached   }   });