public static void register(Observer observer) {
        register(SubjectType.SPRING_CONTENT_REFRESHED.name(), observer);
    }
@Test
    public void testDefaultRegister() {
        AbstractSubjectCenter.register(subjectNotifyListener);
        List<Observer> list = OBSERVERS_MAP.get(AbstractSubjectCenter.SubjectType.SPRING_CONTENT_REFRESHED.name());
        Assert.assertNotNull(list);
        Assert.assertEquals(1, list.size());
        Assert.assertSame(subjectNotifyListener, list.get(0));
        OBSERVERS_MAP.clear();
    }