@Override
      public Object call() {
        Cache cache = getCache();
        LocalRegion region = (LocalRegion) cache.getRegion("region");
        if (region instanceof PartitionedRegion) {
          long total = 0;
          PartitionedRegion pr = ((PartitionedRegion) region);
          for (int i = 0; i < pr.getPartitionAttributes().getTotalNumBuckets(); i++) {
            total += pr.getDataStore().getBucketSize(i);
          }
          return total;
        } else {
          return 0L;
        }
      }
A test of the when we will use the object sizer to determine the actual size of objects wrapped
in CacheDeserializables.



TODO - I was intending to add tests that have an index and object sizer, but it appears we don't
support indexes on regions with overflow to disk.
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/SizingFlagDUnitTest.java