@Override
    public void deregister(ServiceCombRegistration registration) {
        RegisterCenterService registerService = getRegisterCenterService();
        if (registerService == null) {
            LOGGER.severe("registerCenterService is null, fail to unRegister!");
            return;
        }
        registerService.unRegister();
    }
@Test
    public void deregister() {
        registry.deregister(Mockito.mock(ServiceCombRegistration.class));
        Mockito.verify(spyService, Mockito.times(1)).unRegister();
    }