@VisibleForTesting
  protected void addOverflowStatisticsToMBean(Cache cache, AbstractGatewaySender sender) {
    // Get the appropriate mbean and add the overflow stats to it
    LocalRegion lr = (LocalRegion) region;
    ManagementService service = ManagementService.getManagementService(cache);
    if (sender.getId().contains(AsyncEventQueueImpl.ASYNC_EVENT_QUEUE_PREFIX)) {
      AsyncEventQueueMBean bean = (AsyncEventQueueMBean) service.getLocalAsyncEventQueueMXBean(
          AsyncEventQueueImpl.getAsyncEventQueueIdFromSenderId(sender.getId()));

      if (bean != null) {
        // Add the eviction stats
        bean.getBridge().addOverflowStatistics(lr.getEvictionStatistics());

        // Add the disk region stats
        bean.getBridge().addOverflowStatistics(lr.getDiskRegion().getStats().getStats());
      }
    } else {
      GatewaySenderMBean bean =
          (GatewaySenderMBean) service.getLocalGatewaySenderMXBean(sender.getId());

      if (bean != null) {
        // Add the eviction stats
        bean.getBridge().addOverflowStatistics(lr.getEvictionStatistics());

        // Add the disk region stats
        bean.getBridge().addOverflowStatistics(lr.getDiskRegion().getStats().getStats());
      }
    }
  }
Initializes the <code>Region</code> backing this queue. The <code>Region</code>'s scope is
DISTRIBUTED_NO_ACK and mirror type is KEYS_VALUES and is set to overflow to disk based on the
<code>GatewayQueueAttributes</code>.

@param sender The GatewaySender <code>SerialGatewaySenderImpl</code>
@param listener The GemFire <code>CacheListener</code>. The <code>CacheListener</code> can be
       null.
geode-core/src/main/java/org/apache/geode/internal/cache/wan/serial/SerialGatewaySenderQueue.java