protected int compareCell(Cell a, Cell b) {
    int cmp = CellComparator.getInstance().compare(a, b);
    return reversed ? -1 * cmp : cmp;
  }
For each sub-filter in filter list, we save a boolean flag to indicate that whether the return
code of filterCell(c) for sub-filter is INCLUDE* (INCLUDE, INCLUDE_AND_NEXT_COL,
INCLUDE_AND_SEEK_NEXT_ROW) case. if true, we need to transform cell for the sub-filter.
hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FilterListBase.java