int counter = 0;
final Map<Vertex, Long> map = new HashMap<>();
while (traversal.hasNext()) {
counter++;
final Edge edge = traversal.next();
MapHelper.incr(map, edge.iterators().vertexIterator(Direction.OUT).next(), 1l);
}
assertEquals(3, map.size());
assertEquals(5, counter);
map.forEach((k, v) -> {
if (k.id().equals(convertToVertexId("marko"))) {