public static void revoke(Connection connection, final String userName,
    final Permission.Action... actions) throws Throwable {
    connection.getAdmin()
      .revoke(new UserPermission(userName, Permission.newBuilder().withActions(actions).build()));
  }
Revoke global permissions for the specified user.
@param connection The Connection instance to use
hbase-client/src/main/java/org/apache/hadoop/hbase/security/access/AccessControlClient.java