code: @Test public void testTurboDynamicThreshold() throws JoranException {
    configure(ClassicTestConstants.JORAN_INPUT_PREFIX + "turboDynamicThreshold.xml");
    ListAppender listAppender=(ListAppender)root.getAppender("LIST");
    assertEquals(0,listAppender.list.size());
    MDC.put("userId","user1");
    logger.debug("hello user1");
    MDC.put("userId","user2");
    logger.debug("hello user2");
    assertEquals(1,listAppender.list.size());
    ILoggingEvent le=(ILoggingEvent)listAppender.list.get(0);
    assertEquals("hello user2",le.getMessage());
  }
  