code: @Test public void testTurboDynamicThreshold2() throws JoranException {
    configure(ClassicTestConstants.JORAN_INPUT_PREFIX + "turboDynamicThreshold2.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");
    MDC.put("userId","user3");
    logger.debug("hello user3");
    assertEquals(2,listAppender.list.size());
    ILoggingEvent le=(ILoggingEvent)listAppender.list.get(0);
    assertEquals("hello user1",le.getMessage());
    le=(ILoggingEvent)listAppender.list.get(1);
    assertEquals("hello user2",le.getMessage());
  }
  