final List<LogNotificationEvent> events = ComponentUtil.getLogNotificationHelper().drainAll();
        assertEquals(0, events.size());
    }

    @Test
    public void test_append_excludedLogger_notificationHelper() {
        final LogEvent event = createLogEvent(Level.ERROR, "org.codelibs.fess.helper.NotificationHelper", "should be excluded");
        appender.append(event);