@Override
  public void markEndDestroyRegion() {
    onlineMembers.clear();
    offlineMembers.clear();
    equalMembers.clear();
    myInitializedId = null;
    myInitializingId = null;
    aboutToDestroy = false;
    isRecreated = false;
  }
Used to initialize a PlaceHolderDiskRegion for a region that is being closed

@param drv the region that is being closed
geode-core/src/main/java/org/apache/geode/internal/cache/AbstractDiskRegion.java