@Override
  public EvictionController getExistingController(InternalRegionArguments internalArgs) {
    // should never be called so throw an exception
    throw new IllegalStateException(
        "getExistingController should never be called on " + getClass());
  }
Record current RVV to disk and update into disk region RVV.
geode-core/src/main/java/org/apache/geode/internal/cache/DiskRegion.java