public static int calcMemSize(Object o) {
    return calcMemSize(o, null, true);
  }
Return an estimate of the amount of heap memory used for the object. If it is not a byte[] then
account for CachedDeserializable overhead. when it is wrapped by a CachedDeserializable.
geode-core/src/main/java/org/apache/geode/internal/cache/CachedDeserializableFactory.java