@SuppressWarnings("unchecked")
DataSet<Tuple2<Long, Long>> linksInput =env.fromElements(new Tuple2<Long, Long>(1l, 2l));
// assign initial rank to pages
DataSet<Tuple2<Long, Double>> pagesWithRanks = pagesInput.
map(new RankAssigner((1.0d / 10)));
// build adjacency list from link input
DataSet<Tuple2<Long, Long[]>> adjacencyListInput =
linksInput.groupBy(0).reduceGroup(new BuildOutgoingEdgeList());