NavigableSet<byte[]> getCols(String... strCols) {
    NavigableSet<byte[]> cols = new TreeSet<>(Bytes.BYTES_COMPARATOR);
    for (String col : strCols) {
      byte[] bytes = Bytes.toBytes(col);
      cols.add(bytes);
    }
    return cols;
  }
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