- [ ] 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!
```

*
     * @throws Throwable
     */
    protected abstract void doOpen() throws Throwable;
    /**
     * Close client.
     *
     * @throws Throwable
     */
    protected abstract void doClose() throws Throwable;
    /**
     * Connect to server.
     *
     * @throws Throwable
     */
    protected abstract void doConnect() throws Throwable;
    /**
     * disConnect to server.
     *
     * @throws Throwable
     */
    protected abstract void doDisConnect() throws Throwable;
    /**
     * Get the connected channel.
     *
     * @return channel
     */
    protected abstract Channel getChannel();
}