@Override
      public E next() {
        if (cachedHasNext == null) {
          hasNext();
        }
        cachedHasNext = null;
        lastReturned = basicNext();
        return lastReturned;
      }
The n - way merge results returns a sorted results on the cumulative sorted results for
partitioned region based query
geode-core/src/main/java/org/apache/geode/cache/query/internal/NWayMergeResults.java