protected void ApplyChange(Event @event)
 {
     if (@event == null) throw new ArgumentNullException("event");
     @event.SetTimeStamp(DateTimeOffset.Now);
     ApplyChange(@event, true);
 }
 protected void ApplyChange(Event @event)
 {
     if (@event == null) throw new ArgumentNullException("event");
     this.ApplyChange(@event, true);
 }