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操作步骤如下：
1. k8s环境下，consumer端开启mesh模式
2. consumer端需要调用多个provider
3. provider有应用级注册和接口级注册，并且需要的provider不再同一个namespace下
4. 原有项目存在dubbo2.6与3.1多版本间的相互调用，在开启消费端mesh（dubbo3.1）后，无法调用到2.6的服务提供者

**问题：**

1. 如何实现在一个consumer下，调用多个namespace下的provider，并且provider有应用级注册和接口级注册
2. dubbo3.1消费端在开启mesh后，如何调用版本是2.6的服务提供者
*/
    private String services;
    public ReferenceConfig() {
        super();
    }
    public ReferenceConfig(ModuleModel moduleModel) {
        super(moduleModel);
    }
    public ReferenceConfig(Reference reference) {
        super(reference);
    }
    public ReferenceConfig(ModuleModel moduleModel, Reference reference) {
        super(moduleModel, reference);
    }
    @Override
    protected void postProcessAfterScopeModelChanged(ScopeModel oldScopeModel, ScopeModel newScopeModel) {
        super.postProcessAfterScopeModelChanged(oldScopeModel, newScopeModel);
        protocolSPI = this.getExtensionLoader(Protocol.class).getAdaptiveExtension();
        proxyFactory = this.getExtensionLoader(ProxyFactory.class).getAdaptiveExtension();
    }
    /**
     * Get a string presenting the service names that the Dubbo interface subscribed.
     * If it is a multiple-values, the content will be a comma-delimited String.
     *
     * @return non-null
     * @see RegistryConstants#SUBSCRIBED_SERVICE_NAMES_KEY
     * @since 2.7.8
     */
    @Deprecated
    @Parameter(key = SUBSCRIBED_SERVICE_NAMES_KEY)