@Override
    public Collection<ServiceInstance> getInstances(String serviceId) throws QueryInstanceException {
        return zkServiceManager.chooseService().getInstances(serviceId);
    }
@Test
    public void getInstances() {
        String serviceName = "test1";
        try {
            Mockito.when(zkService34.getInstances(serviceName)).thenReturn(Collections.emptyList());
        } catch (QueryInstanceException e) {
            e.printStackTrace();
        }
        try {
            Assert.assertEquals(zkDiscoveryClient.getInstances(serviceName), Collections.emptyList());
        } catch (QueryInstanceException e) {
            e.printStackTrace();
        }
    }