add: return null; 
context:   QueryInterface : function(iid)    {    if(iid.equals(Components.interfaces.nsIXULBrowserWindow))      return this;    throw Components.results.NS_NOINTERFACE;    },
meta: 8395	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/8395/244053ab13271ef67576fad983b62fa798c85a32/mini-nav.js/clean/embedding/browser/chrome/content/mini-nav.js