@Override
  public int hashCode() {
    int h = 0;
    for (final Entry entry : (Iterable<Entry>) entrySet()) {
      h += entry.hashCode();
    }
    return h;
  }
hashCode is over-ridden to make sure it is based on the objects we expose and not the internal
CachedDeserializables.
geode-core/src/main/java/org/apache/geode/cache/operations/internal/UpdateOnlyMap.java