@Override
  public boolean equals(Object obj) {
    if (!(obj instanceof SelectResults)) {
      return false;
    }
    if (!collectionType.equals(((SelectResults) obj).getCollectionType())) {
      return false;
    }
    return base.equals(obj);
  }
no-arg constructor required for DataSerializable
geode-core/src/main/java/org/apache/geode/cache/query/internal/ResultsCollectionWrapper.java