@Override
    protected void closeTable() {
      for (Table table : userVsTable.values()) {
        try {
          table.close();
        } catch (Exception e) {
          LOG.error("Error while closing the table " + 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/MultiThreadedReaderWithACL.java