@Override
  public CachePerfStats getRegionPerfStats() {
    PartitionedRegionDataStore ds = getDataStore();
    CachePerfStats result = null;
    if (ds != null) {
      // If we don't have a data store (we are an accessor)
      // then we do not have per region stats.
      // This is not good. We should still have stats even for accessors.
      result = ds.getCachePerfStats(); // fixes 46692
    }
    return result;
  }
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