public static void setInstances(String serviceId, List<ServiceInstance> instances) {
		instancesMap.put(serviceId, Collections.unmodifiableList(instances));
	}
Set instances for specific service.
@param serviceId service id
@param instances service instances
spring-cloud-alibaba-starters/spring-cloud-starter-alibaba-nacos-discovery/src/main/java/com/alibaba/cloud/nacos/discovery/ServiceCache.java