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

![image](https://user-images.githubusercontent.com/8758457/59562427-2e06c800-905f-11e9-9bff-9ea54d87fc6d.png)
![image](https://user-images.githubusercontent.com/8758457/59562435-51317780-905f-11e9-930b-a66bc866ccf1.png)


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!
```

}
    @Override
    public boolean containsValue(Object value) {
        return delegateMap.containsValue(value);
    }
    @Override
    public int size() {
        return delegateMap.size();
    }
    @Override
    public boolean isEmpty() {
        return delegateMap.isEmpty();
    }
    @Override
    public void clear() {
        delegateMap.clear();
        expireThread.stopExpiring();
    }
    @Override
    public int hashCode() {
        return delegateMap.hashCode();
    }
    @Override
    public Set<K> keySet() {
        return delegateMap.keySet();
    }
    @Override
    public boolean equals(Object obj) {
        return delegateMap.equals(obj);
    }