rem: if (this.mCreationDate) this.mCreationDate.makeImmutable(); 
add: this.mCreationDate.makeImmutable();  
context:     makeItemBaseImmutable: function() {        if (this.mImmutable)            throw Components.results.NS_ERROR_FAILURE;        if (this.mCreationDate)            this.mCreationDate.makeImmutable();        if (this.mRecurrenceInfo)            this.mRecurrenceInfo.makeImmutable();        if (this.mAlarmTime)            this.mAlarmTime.makeImmutable();        for (var i = 0; i < this.mAttendees.length; i++)            this.mAttendees[i].makeImmutable();        this.mImmutable = true;    },
meta: 10234	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/10234/9a9719b366d04d5db90dfcb7e370af554ae5c045/calItemBase.js/clean/calendar/base/src/calItemBase.js