private static void cleanUp() throws Exception {
    // Clean the _acl_ table
    try {
      deleteTable(TEST_UTIL, TEST_TABLE);
    } catch (TableNotFoundException ex) {
      // Test deleted the table, no problem
      LOG.info("Test deleted table " + TEST_TABLE);
    }
    // Verify all table/namespace permissions are erased
    assertEquals(0, PermissionStorage.getTablePermissions(conf, TEST_TABLE).size());
    assertEquals(0,
      PermissionStorage.getNamespacePermissions(conf, TEST_TABLE.getNamespaceAsString()).size());
  }
The systemUserConnection created here is tied to the system user. In case, you are planning to
create AccessTestAction, DON'T use this systemUserConnection as the 'doAs' user gets eclipsed
by the system user.
hbase-server/src/test/java/org/apache/hadoop/hbase/security/access/TestAccessController.java