private boolean isDeletedByDeleteFamily(ExtendedCell cell) {
    return deleteFamily != null && (deleteFamily.getTimestamp() > cell.getTimestamp()
      || (deleteFamily.getTimestamp() == cell.getTimestamp()
        && (!newVersionBehavior || cell.getSequenceId() < deleteFamily.getSequenceId())));
  }
@param dir Directory to create file in.
@return random filename inside passed <code>dir</code>
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/StoreFileWriter.java