@Override
    protected void resetKVHeap(List<? extends KeyValueScanner> scanners, CellComparator comparator)
      throws IOException {
      if (count == null) {
        count = new AtomicInteger(0);
      }
      heap = newKVHeap(scanners, comparator);
    }
A StoreScanner for our CELL_GRID above. Fakes the block transitions. Does counts of calls to
optimize and counts of when optimize actually did an optimize.
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestStoreScanner.java