### Question:
ServiceManager implements RecordListener<Service> { public int getResponsibleInstanceCount() { Map<String, Set<Service>> responsibleServices = getResponsibleServices(); int count = 0; for (String namespaceId : responsibleServices.keySet()) { for (Service service : responsibleServices.get(namespaceId)) { count += service.allIPs().size(); } } return count; } ServiceManager(SwitchDomain switchDomain, DistroMapper distroMapper, ServerMemberManager memberManager,
            PushService pushService, RaftPeerSet raftPeerSet); @PostConstruct void init(); Map<String, Service> chooseServiceMap(String namespaceId); void addUpdatedServiceToQueue(String namespaceId, String serviceName, String serverIP, String checksum); @Override boolean interests(String key); @Override boolean matchUnlistenKey(String key); @Override void onChange(String key, Service service); @Override void onDelete(String key); RaftPeer getMySelfClusterState(); void updatedHealthStatus(String namespaceId, String serviceName, String serverIP); Set<String> getAllServiceNames(String namespaceId); Map<String, Set<String>> getAllServiceNames(); Set<String> getAllNamespaces(); List<String> getAllServiceNameList(String namespaceId); Map<String, Set<Service>> getResponsibleServices(); int getResponsibleServiceCount(); int getResponsibleInstanceCount(); void easyRemoveService(String namespaceId, String serviceName); void addOrReplaceService(Service service); void createEmptyService(String namespaceId, String serviceName, boolean local); void createServiceIfAbsent(String namespaceId, String serviceName, boolean local, Cluster cluster); void registerInstance(String namespaceId, String serviceName, Instance instance); void updateInstance(String namespaceId, String serviceName, Instance instance); void addInstance(String namespaceId, String serviceName, boolean ephemeral, Instance... ips); void removeInstance(String namespaceId, String serviceName, boolean ephemeral, Instance... ips); Instance getInstance(String namespaceId, String serviceName, String cluster, String ip, int port); List<Instance> updateIpAddresses(Service service, String action, boolean ephemeral, Instance... ips); Service getService(String namespaceId, String serviceName); boolean containService(String namespaceId, String serviceName); void putService(Service service); List<Service> searchServices(String namespaceId, String regex); int getServiceCount(); int getInstanceCount(); int getPagedService(String namespaceId, int startPage, int pageSize, String param, String containedInstance,
            List<Service> serviceList, boolean hasIpCount);  }### Answer:
@Test public void getResponsibleInstanceCount() throws NacosException { when(distroMapper.responsible(TEST_SERVICE_NAME)).thenReturn(true); assertEquals(0, serviceManager.getResponsibleInstanceCount()); serviceManager.createEmptyService(TEST_NAMESPACE, TEST_SERVICE_NAME, true); Service service = serviceManager.getService(TEST_NAMESPACE, TEST_SERVICE_NAME); service.addCluster(cluster); ((Set<Instance>) ReflectionTestUtils.getField(cluster, "ephemeralInstances")).add(instance); assertEquals(1, serviceManager.getResponsibleInstanceCount()); }