code: Resilience getDefaultResilience()
      {
          if (default_resilience != null)
              return default_resilience;
  
          if (parent_queue != null)
              return parent_queue.getDefaultResilience();
  
          return null;
      }
docs: Gets the Queues default Resilience. Will ask the parent Queue
  to get its default Resilience if this Queue doesn't have one.