@Override
    protected void closeHTable() {
      try {
        if (table != null) {
          table.close();
        }
        for (Table table : userVsTable.values()) {
          try {
            table.close();
          } catch (Exception e) {
            LOG.error("Error while closing the table " + table.getName(), e);
          }
        }
      } catch (Exception e) {
        LOG.error("Error while closing the HTable " + table.getName(), e);
      }
    }
Maps user with Table instance. Because the table instance has to be created per user inorder to
work in that user's context
hbase-diagnostics/src/main/java/org/apache/hadoop/hbase/util/MultiThreadedUpdaterWithACL.java