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？
private static final long serialVersionUID = -5864351140409987595L;
    /**
     * The {@link Protocol} implementation with adaptive functionality,it will be different in different scenarios.
     * A particular {@link Protocol} implementation is determined by the protocol attribute in the {@link URL}.
     * For example:
     *
     * <li>when the url is registry://224.5.6.7:1234/org.apache.dubbo.registry.RegistryService?application=dubbo-sample,
     * then the protocol is <b>RegistryProtocol</b></li>
     *
     * <li>when the url is dubbo://224.5.6.7:1234/org.apache.dubbo.config.api.DemoService?application=dubbo-sample, then
     * the protocol is <b>DubboProtocol</b></li>
     * <p>
     * Actually，when the {@link ExtensionLoader} init the {@link Protocol} instants,it will automatically wraps two
     * layers, and eventually will get a <b>ProtocolFilterWrapper</b> or <b>ProtocolListenerWrapper</b>