@Override
  public KnownVersion[] getSerializationVersions() {
    return null;
  }
Returning zero as default size. This is because this method will be called only in case of
ha-overflow, in which case, we ignore size of instances of <code>HAEventWrapper</code>, as they
are never overflown to disk.

@return int Size of this instance in bytes.
geode-core/src/main/java/org/apache/geode/internal/cache/tier/sockets/HAEventWrapper.java