internal void RefEvents()
 {
     if (events_ref_count == 0)
     {
         if (event_subscriber == null)
         {
             event_subscriber = new EventSubscriber(this);
         }
         if (service_description.EventUrl == null)
         {
             // We log this because it's a no-no to throw in event registration
             Log.Exception(new InvalidOperationException(
                               "Attempting to subscribe to events for a service with no event URL."));
         }
         else
         {
             event_subscriber.Start();
         }
     }
     events_ref_count++;
 }