Opinion Miner

http://www.ibm.com/developerworks/library/bd-avrohadoop/index.html?ca=dat

http://blog.51yip.com/mysql/1029.html

http://stackoverflow.com/questions/41031166/scala-extends-vs-with

http://alvinalexander.com/scala/how-to-use-case-classes-in-scala-match-expressions