泛化调用中
```java
public interface GenericService {

    Object $invoke(String method, String[] parameterTypes, Object[] args) throws GenericException;

}
```
这里可不可以异步调用返回个Future。我的工具实现会有多个 `ReferenceConfig` 缓存，我可以单独再用一个线程池来作为 `$invoke` 的执行上下文。但每个 `ReferenceConfig` 好像都有一组线程来维持，这个本身能不能异步调用？
* The url for peer-to-peer invocation
     */
    private String url;
    /**
     * The method configs
     */
    private List<MethodConfig> methods;
    /**
     * The consumer config (default)
     */
    private ConsumerConfig consumer;
    /**
     * Only the service provider of the specified protocol is invoked, and other protocols are ignored.
     */
    private String protocol;
    /**
     * The interface proxy reference
     */
    private transient volatile T ref;
    /**
     * The invoker of the reference service
     */
    private transient volatile Invoker<?> invoker;
    /**
     * The flag whether the ReferenceConfig has been initialized
     */
    private transient volatile boolean initialized;
    /**
     * whether this ReferenceConfig has been destroyed
     */