rem: return this; 
add: Components.returnCode = Components.results.NS_ERROR_NO_INTERFACE; return null; 
context:     QueryInterface: function( iid )    {        if (!iid.equals(Components.interfaces.nsISupports) &&            !iid.equals(Components.interfaces.nsIXPIProgressDialog))            throw Components.results.NS_ERROR_NO_INTERFACE;        return this;    }
meta: 5872	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/5872/55a5e5ddbf4a7e9103b995d808c4466085d2123f/xpistatus.js/buggy/xpinstall/res/content/xpistatus.js