static Iterator shuffleIterator(Iterator iter) {
        List list = IteratorUtils.toList(iter);
        Collections.shuffle(list);
        return list.iterator();
    }
@author Cole Greer (https://github.com/Cole-Greer)
tinkergraph-gremlin/src/test/java/org/apache/tinkerpop/gremlin/tinkergraph/structure/TinkerShuffleGraph.java