protected PartitionedRegion getRandomShadowPR() {
    PartitionedRegion prQ = null;
    if (userRegionNameToShadowPRMap.values().size() > 0) {
      int randomIndex = new Random().nextInt(userRegionNameToShadowPRMap.size());
      prQ = (PartitionedRegion) userRegionNameToShadowPRMap.values().toArray()[randomIndex];
    }
    return prQ;
  }
Returns the set of shadowPR backign this queue.
geode-core/src/main/java/org/apache/geode/internal/cache/wan/parallel/ParallelGatewaySenderQueue.java