@Test
	public void testCacheIsOK() throws NacosException {
		when(serviceDiscovery.getInstances("a"))
				.thenReturn(singletonList(serviceInstance));
		this.client.getInstances("a");
		assertThat(ServiceCache.getInstances("a")).isEqualTo(singletonList(serviceInstance));
	}
@author xiaojing
@author echooymxq
@author freeman
spring-cloud-alibaba-starters/spring-cloud-starter-alibaba-nacos-discovery/src/test/java/com/alibaba/cloud/nacos/NacosDiscoveryClientTests.java