public override IQueue CreateQueueForWorker(Worker worker)
 {
     using (RWLock.AsWriter(_lock))
       {
     QueueOfRunnables queue = new QueueOfRunnables();
     _queues.Add(queue);
     return queue;
       }
 }
 protected virtual void RetireQueueUnderLock(QueueOfRunnables queue)
 {
 }