rem: event.calendar.modifyItem(event, itemToDelete.parentItem, null); 
add: doTransaction('modify', event, event.calendar, itemToDelete.parentItem, null); 
context:     deleteOccurrence: function (aOccurrence) {        var itemToDelete = getOccurrenceOrParent(aOccurrence);        if (itemToDelete.parentItem != itemToDelete) {            var event = itemToDelete.parentItem.clone();            event.recurrenceInfo.removeOccurrenceAt(itemToDelete.recurrenceId);            event.calendar.modifyItem(event, itemToDelete.parentItem, null);        } else {            aOccurrence.calendar.deleteItem(itemToDelete, null);        }    }
meta: 10234	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/10234/dfb1c04b7b37bedca7fd02a138b9a504933f4ebc/calendar-management.js/clean/calendar/lightning/content/calendar-management.js