title: Difference between Class.override() vs Ext.define('Class', override: 'Class' ... to create an override
body: <p><strong>What's the difference between these 2 override</strong></p>
  
  <p>So option 1: </p>
  
  <pre><code>Ext.window.Window.override({
      initComponent: function () {
          this.draggable = false;
          this.resizable = false;
  
          this.on('resize', function () {
              this.center();
          });
  
          this.callParent();
      }
  });
  </code></pre>
  
  <p>option 2:</p>
  
  <pre><code>Ext.define('Ext.window.WindowOverride', {
      override: 'Ext.window.Window',
  
      initComponent: function () {
          this.draggable = false;
          this.resizable = false;
  
          this.on('resize', function () {
              this.center();
          });
  
          this.callParent();
      }
  });
  </code></pre>
  
  <p><strong>Which approach should I follow and why?</strong></p>
  
  <p><em>Specifically using Extjs 4.1.1</em></p>