- [ ] I have searched the [issues](https://github.com/apache/incubator-dubbo/issues) of this repository and believe that this is not a duplicate.
- [ ] I have checked the [FAQ](https://github.com/apache/incubator-dubbo/blob/master/FAQ.md) of this repository and believe that this is not a duplicate.

### Environment

* Dubbo version: xxx
* Operating System version: xxx
* Java version: xxx

### Steps to reproduce this issue

1. xxx
2. xxx
3. xxx

Pls. provide [GitHub address] to reproduce this issue.

### Expected Result

What do you expected from the above steps？

### Actual Result

What actually happens?

If there is an exception, please attach the exception trace:

```
Just put your stack trace here!
```

private final Invoker<T> invoker;
        /**
         * @param invoker
         * @param url     invoker.getUrl return this value
         */
        public InvokerDelegate(Invoker<T> invoker, URL url) {
            super(invoker, url);
            this.invoker = invoker;
        }
        public Invoker<T> getInvoker() {
            if (invoker instanceof InvokerDelegate) {
                return ((InvokerDelegate<T>) invoker).getInvoker();
            } else {
                return invoker;
            }
        }
    }
    static private class DestroyableExporter<T> implements Exporter<T> {