public boolean removeNamespaceAccessAcl(TableName tableName, Set<String> removeUsers,
    String operation) {
    try {
      long start = EnvironmentEdgeManager.currentTime();
      if (removeUsers.size() > 0) {
        handleNamespaceAccessAcl(tableName.getNamespaceAsString(), removeUsers,
          HDFSAclOperation.OperationType.REMOVE);
      }
      LOG.info("Remove HDFS acl when {} table {}, cost {} ms", operation, tableName,
        EnvironmentEdgeManager.currentTime() - start);
      return true;
    } catch (Exception e) {
      LOG.error("Remove HDFS acl error when {} table {}", operation, tableName, e);
      return false;
    }
  }
Remove table access acl from namespace dir when delete table
@param tableName   the table
@param removeUsers the users whose access acl will be removed
@return false if an error occurred, otherwise true
hbase-server/src/main/java/org/apache/hadoop/hbase/security/access/SnapshotScannerHDFSAclHelper.java