@Override
  // called between every row.
  public void reset() {
    hasFamilyStamp = false;
    familyStamp = 0L;
    familyVersionStamps.clear();
    deleteCell = null;
  }
Check if the specified Cell buffer has been deleted by a previously seen delete.
@param cell - current cell to check if deleted by a previously seen delete
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/querymatcher/ScanDeleteTracker.java