getContributorCounts method in a functional style

getContributorCountsFunctional.java

public List<ContributorCount> getContributorCounts(){
    List<ArticleView> articleViews = getArticleViews(); 
    
    return articleViews
            .map(a -> a.contributor)        //Get the contributor names from the article views
            .sort(Ord.stringOrd)            //Need to sort before grouping
            .group(Equal.stringEqual)       //Group by contributor name
            .filter(l -> l.length() > 1)    //remove any contributors who only appear once
            .map(l -> new ContributorCount(l.head(), l.length())); //Map to the return type
}