@VisibleForTesting
  public void dumpBackingMap() {
    synchronized (entries) {
      if (entries instanceof AbstractRegionMap) {
        ((AbstractRegionMap) entries).verifyTombstoneCount(tombstoneCount);
      }
      logger.debug("Dumping region of size {} tombstones: {}: {}", size(), getTombstoneCount(),
          toString());
      if (entries instanceof AbstractRegionMap) {
        ((AbstractRegionMap) entries).dumpMap();
      }
    }
  }
test hook - dump the backing map for this region
geode-core/src/main/java/org/apache/geode/internal/cache/LocalRegion.java