@Test
    @LoadGraphWith(MODERN)
    public void g_V_fold() {
        final Traversal<Vertex, List<Vertex>> traversal = get_g_V_fold();
        printTraversalForm(traversal);
        final List<Vertex> list = traversal.next();
        assertFalse(traversal.hasNext());
        final Set<Vertex> vertices = new HashSet<>(list);
        assertEquals(6, vertices.size());
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-test/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/map/FoldTest.java