add: if (this.mEtag) { var httpchannel = aChannel.QueryInterface(Components.interfaces.nsIHttpChannel);   httpchannel.setRequestHeader("If-None-Match", this.mEtag, false); }  
context:     onBeforeGet: function(aChannel) {        this.mChannel = aChannel;        return true;    },
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/0defd389125b4b1ab8c53a084d478f9dd695fe02/calICSCalendar.js/buggy/calendar/providers/ics/calICSCalendar.js