@Override
      public E next() {
        if (lastReturnedIteratorIndex != -1) {
          iterators[lastReturnedIteratorIndex].move();
        }
        return basicNext();
      }
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