@Override
  public Object getValueOnDiskOrBuffer(InternalRegion region) throws EntryNotFoundException {
    // @todo darrel if value is Token.REMOVED || Token.DESTROYED throw
    // EntryNotFoundException
    return Helper.getValueOnDiskOrBuffer(this, region.getDiskRegion(), region);
  }
Abstract implementation class of RegionEntry interface. This is adds Disk support behavior

@since GemFire 3.5.1
geode-core/src/main/java/org/apache/geode/internal/cache/entries/AbstractOplogDiskRegionEntry.java