List<LogNotificationEvent> events = helper.drainAll();
        assertNotNull(events);
        assertTrue(events.isEmpty());
    }

    @Test
    public void test_drainAll_clears() {
        LogNotificationHelper helper = new LogNotificationHelper();
        helper.offer(new LogNotificationEvent(1000L, "ERROR", "org.test", "msg", null));
        List<LogNotificationEvent> first = helper.drainAll();