boolean isDREvent(InternalCache cache, GatewaySenderEventImpl event) {
    Region region = cache.getRegion(event.getRegionPath());
    return region instanceof DistributedRegion;
  }
Returns the set of shadowPR backign this queue.
geode-core/src/main/java/org/apache/geode/internal/cache/wan/parallel/ParallelGatewaySenderQueue.java