@Override
    public CachedDeserializable next() {
      java.util.Map.Entry<Pair<CachedDeserializable, CachedDeserializable>, CachedDeserializable> next =
          iterator.next();
      return next.getKey().getY();

    }
A dummy implementation of an IndexMap. Keeps all of the entries in memory, but in serialized
form.
geode-core/src/main/java/org/apache/geode/internal/cache/persistence/query/mock/IndexMapImpl.java