rem: this.mCalendar.addItem(this.mItem, null); 
add: this.mCalendar.addItem(this.mItem, this); 
context:     undoTransaction: function () {        switch (this.mAction) {            case 'add':                this.mCalendar.deleteItem(this.mItem, null);                break;            case 'modify':                this.mCalendar.modifyItem(this.mOldItem, this.mItem, null);                break;            case 'delete':                this.mCalendar.addItem(this.mItem, null);                break;            case 'move':                this.mCalendar.deleteItem(this.mItem, this.mListener);                this.mOldCalendar.addItem(this.mOldItem, this.mListener);                break;        }    },
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/cad58b43fc428e076fd03d62a641786c7b60b226/calendar-item-editing.js/buggy/calendar/base/content/calendar-item-editing.js