@Override
	protected NacosRegistration getRegistration() {
		if (this.registration.getPort() < 0 && this.getPort().get() > 0) {
			this.registration.setPort(this.getPort().get());
		}
		Assert.isTrue(this.registration.getPort() > 0, "service.port has not been set");
		return this.registration;
	}
@author xiaojing
@author <a href="mailto:mercyblitz@gmail.com">Mercy</a>
spring-cloud-alibaba-starters/spring-cloud-starter-alibaba-nacos-discovery/src/main/java/com/alibaba/cloud/nacos/registry/NacosAutoServiceRegistration.java