@Override
    public ScanType getScanType(CompactionRequestImpl request) {
      // If majorRangeFromRow and majorRangeToRow are not null, then we will not use the return
      // value to create InternalScanner. See the createScanner method below. The return value is
      // also used when calling coprocessor hooks.
      return ScanType.COMPACT_RETAIN_DELETES;
    }
This is the placeholder for stripe compactor. The implementation, as well as the proper javadoc,
will be added in HBASE-7967.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/compactions/StripeCompactor.java