@Override
    public void fromData(DataInput in) throws IOException, ClassNotFoundException {
      value = DataSerializer.readString(in);
    }
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