- [ ] 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 void putAll(Map<? extends K, ? extends V> inMap) {
        for (Entry<? extends K, ? extends V> e : inMap.entrySet()) {
            this.put(e.getKey(), e.getValue());
        }
    }
    @Override
    public Collection<V> values() {
        List<V> list = new ArrayList<V>();
        Set<Entry<K, ExpiryObject>> delegatedSet = delegateMap.entrySet();
        for (Entry<K, ExpiryObject> entry : delegatedSet) {
            ExpiryObject value = entry.getValue();
            list.add(value.getValue());
        }
        return list;
    }
    @Override
    public Set<Entry<K, V>> entrySet() {
        throw new UnsupportedOperationException();
    }
    public ExpireThread getExpireThread() {
        return expireThread;
    }
    public int getExpirationInterval() {
        return expireThread.getExpirationInterval();
    }
    public void setExpirationInterval(int expirationInterval) {
        expireThread.setExpirationInterval(expirationInterval);
    }
    public int getTimeToLive() {