@Override
  public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result + ((x == null) ? 0 : x.hashCode());
    result = prime * result + ((y == null) ? 0 : y.hashCode());
    return result;
  }
An object that holds a pair of objects.
geode-core/src/main/java/org/apache/geode/internal/cache/persistence/query/mock/Pair.java