protected void setCurrentCell(ExtendedCell newVal) throws IOException {
    this.cur = newVal;
    if (this.cur != null && this.reader.isBulkLoaded() && !this.reader.isSkipResetSeqId()) {
      PrivateCellUtil.setSequenceId(cur, this.reader.getSequenceID());
    }
  }
Get scanners for compaction. We will create a separated reader for each store file to avoid
contention with normal read request.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/StoreFileScanner.java