@Override
    public boolean start() {
        if (namingService == null) {
            if (LOGGER.isWarnEnabled()) {
                LOGGER.warn("Nacos client should be initialized before starting.");
            }
            return false;
        }
        return true;
    }
Instantiates a new Nacos registry.

@param registryConfig the registry config
registry/registry-nacos/src/main/java/com/alipay/sofa/rpc/registry/nacos/NacosRegistry.java