@Override
  public Configuration getConf() {
    return this.conf;
  }
This is an implementation for ScanLabelGenerator. It will extract labels from passed in
authorizations and cross check against the set of predefined authorization labels for given user.
The labels for which the user is not authorized will be dropped.
hbase-server/src/main/java/org/apache/hadoop/hbase/security/visibility/DefinedSetFilterScanLabelGenerator.java