public boolean isSubscriberRegistered(String serviceName, String groupName, String cluster) {
        String key = ServiceInfo.getKey(NamingUtils.getGroupedName(serviceName, groupName), cluster);
        synchronized (subscribes) {
            SubscriberRedoData redoData = subscribes.get(key);
            return null != redoData && redoData.isRegistered();
        }
    }
@Test
    void testIsSubscriberRegistered() {
        assertFalse(redoService.isSubscriberRegistered(SERVICE, GROUP, CLUSTER));
        redoService.cacheSubscriberForRedo(SERVICE, GROUP, CLUSTER);
        redoService.subscriberRegistered(SERVICE, GROUP, CLUSTER);
        assertTrue(redoService.isSubscriberRegistered(SERVICE, GROUP, CLUSTER));
    }