public Operation newOp(final MemcachedNode n,
          final CountDownLatch latch) {
        return opFact.noop(new OperationCallback() {
          public void complete() {
            latch.countDown();
          }

          public void receivedStatus(OperationStatus s) {
            // Nothing special when receiving status, only
            // necessary to complete the interface
          }
        });
      }
Wait for the queues to die down.

@param timeout the amount of time time for shutdown
@param unit the TimeUnit for the timeout
@return result of the request for the wait
@throws IllegalStateException in the rare circumstance where queue is too
          full to accept any more requests
src/main/java/net/spy/memcached/TapConnectionProvider.java