public static int calcSerializedMemSize(Object o) {
    int result = calcSerializedSize(o);
    result += Sizeable.PER_OBJECT_OVERHEAD;
    if (!(o instanceof byte[])) {
      result += overhead();
    }
    return result;
  }
Return how much memory this object will consume if it is in serialized form

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