tree 69bfeae4e5b17abc85433f5f3914242d747c3907
parent fb6af3cbd393439568df739eb59b056dbd9feabb
author qixiaobo <qixiaobo.nj@gmail.com> 1564142304 +0800
committer qixiaobo <qixiaobo.nj@gmail.com> 1564142304 +0800

maybe we hava a method without args
so it make a npe like below
```
Exception in thread "Dubbo-proxy-request-worker-pool-thread-3" java.lang.NullPointerException
        at org.apache.dubbo.proxy.worker.RequestWorker.run(RequestWorker.java:65)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
        at java.lang.Thread.run(Thread.java:748)
```