@Override
    public void unsubscribeService(Service service, Subscriber subscriber, String clientId) {
        Service singleton = ServiceManager.getInstance().getSingletonIfExist(service).orElse(service);
        Client client = clientManager.getClient(clientId);
        checkClientIsLegal(client, clientId);
        client.removeServiceSubscriber(singleton);
        client.setLastUpdatedTime();
        NotifyCenter.publishEvent(new ClientOperationEvent.ClientUnsubscribeServiceEvent(singleton, clientId));
    }
@Test
    void testUnSubscribeWhenClientPersistent() {
        assertThrows(NacosRuntimeException.class, () -> {
            Client persistentClient = new IpPortBasedClient(ipPortBasedClientId, false);
            when(clientManager.getClient(anyString())).thenReturn(persistentClient);
            // Excepted exception
            ephemeralClientOperationServiceImpl.unsubscribeService(service, subscriber, ipPortBasedClientId);
        });
    }