@Override
  public CloseableIterator<IndexEntry> descendingIterator(Object end, boolean endInclusive) {
    byte[] endBytes = endInclusive ? ByteComparator.MAX_BYTES : ByteComparator.MIN_BYTES;
    return new Itr(
        map.headMap(new Pair(end, endBytes), endInclusive).descendingMap().entrySet().iterator());
  }
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