public int getPerEntryLRUOverhead() {
    if (dataStore == null) { // this is an accessor
      return -1;
    }
    try {
      return dataStore.getPerEntryLRUOverhead();
    } catch (NoSuchElementException ignore) { // no buckets available
      return -1;
    }
  }
Test hook to return the per entry overhead for a bucket region. Returns -1 if no buckets exist
in this vm.

@since GemFire 6.1.2.9
geode-core/src/main/java/org/apache/geode/internal/cache/PartitionedRegion.java