Github user jongyoul commented on the issue:
https://github.com/apache/zeppelin/pull/3158
@felixcheung IntelliJ's lambda format was not matched in our current
checkstyle. I've tried to fix it by changing checkstyle, but I felt depressed
because we should do every time whenever this inconsistency occurs. So I
thought it would be better to change IDE's style and maven formatter to the
same tool. That's the basic reason why I'd like to change style-related plugins---
