add: if (this.findCalendarID(calendar) in this.mCache) { throw "Can't delete a registered calendar"; } 
context:     deleteCalendar: function(calendar) {        /* check to see if calendar is unregistered first... */        /* delete the calendar for good */                this.notifyObservers("onCalendarDeleting", [calendar]);    },
meta: 5872	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/5872/501cbd1b9c8481004847ae524a5940a959bf3b34/calCalendarManager.js/buggy/calendar/base/src/calCalendarManager.js