public PartitionedRegion getRegion(String fullpath) {
    return userRegionNameToShadowPRMap.get(fullpath);
  }
This returns queueRegion if there is only one PartitionedRegion using the GatewaySender
Otherwise it returns null.
geode-core/src/main/java/org/apache/geode/internal/cache/wan/parallel/ParallelGatewaySenderQueue.java