topology
.newStream("tweets", spout)
.each(new Fields("str"), new ParseTweet(), new Fields("text", "content", "user"))
.project(new Fields("content", "user"))
.each(new Fields("content"), new OnlyHashtags())
.each(new Fields("user"), new OnlyEnglish())
.each(new Fields("content", "user"), new ExtractFollowerClassAndContentName(), new Fields("followerClass", "contentName"))
.groupBy(new Fields("followerClass", "contentName"))
.persistentAggregate(new MemoryMapState.Factory(), new Count(), new Fields("count"))
;