@Bean
	@ConditionalOnMissingBean
	@ConditionalOnProperty(value = "spring.cloud.nacos.discovery.watch.enabled", matchIfMissing = false)
	public NacosWatch nacosWatch(NacosServiceManager nacosServiceManager,
			NacosDiscoveryProperties nacosDiscoveryProperties) {
		return new NacosWatch(nacosServiceManager, nacosDiscoveryProperties);
	}
NacosWatch is no longer enabled by default .
see https://github.com/alibaba/spring-cloud-alibaba/issues/2868
spring-cloud-alibaba-starters/spring-cloud-starter-alibaba-nacos-discovery/src/main/java/com/alibaba/cloud/nacos/discovery/NacosDiscoveryClientConfiguration.java