SerialGatewaySenderQueueMetaRegion newMetaRegion(InternalCache cache,
        final String regionName,
        final RegionAttributes<?, ?> ra,
        AbstractGatewaySender sender) {
      return new SerialGatewaySenderQueueMetaRegion(regionName, ra, null, cache, sender,
          sender.getStatisticsClock());
    }
shutdown this thread and the caller thread will join this thread
geode-core/src/main/java/org/apache/geode/internal/cache/wan/serial/SerialGatewaySenderQueue.java