@Override
  public void init(Map<String, Object> params) {
    if (params != null && params.containsKey(HMaster.MASTER)) {
      this.master = (HMaster) params.get(HMaster.MASTER);
    }
  }
Implementation of a file cleaner that checks if a empty directory with no subdirs and subfiles is
deletable when user scan snapshot feature is enabled
hbase-server/src/main/java/org/apache/hadoop/hbase/security/access/SnapshotScannerHDFSAclCleaner.java