public override void OnNext(JournalEvent next)
 {
     try
     {
         lock (Observers)
             Observers.AsParallel().ExecuteManyWithAggregateException(i => i.OnNext(next));
     }
     catch (Exception e)
     {
         Log.Error(e, "Error caught in Async Broker");
     }
 }
 public override void OnCompleted()
 {
     try
     {
         lock (Observers)
             Observers.AsParallel().ExecuteManyWithAggregateException(i => i.OnCompleted());
     }
     catch (Exception e)
     {
         Log.Error(e, "Error caught in Async Broker");
     }
 }