working with combine adjacent keywords

note: difference between my implementation and whats in the textrank
paper: i am ranking single words, combing all the ones that occur
adjacent then taking the top ⅓*numberOfSingleWordsThatPassedTagFilet IE
numberOf Vertices in the graph
whereas what the paper says is that they take top ⅓ of single words and
combine them where they are adjacent however even their own example in
the paper seems inconsistent with this