rem: return this; 
add: return this; 
context:   QueryInterface : function(iid)  {    if (iid.equals(Components.interfaces.nsIDownloadProgressListener) ||        iid.equals(Components.interfaces.nsISupports))    return this;    throw Components.results.NS_NOINTERFACE;  },
meta: 10520	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/10520/c816c402c2dc9a4ba3e0172325a9186da0704138/DownloadProgressListener.js/clean/toolkit/mozapps/downloads/content/DownloadProgressListener.js