@Test
    @FeatureRequirement(featureClass = Graph.Features.EdgeFeatures.class, feature = Graph.Features.EdgeFeatures.FEATURE_ADD_EDGES)
    @FeatureRequirement(featureClass = Graph.Features.VertexFeatures.class, feature = Graph.Features.VertexFeatures.FEATURE_ADD_VERTICES)
    public void shouldTraverseInOutFromVertexWithSingleEdgeLabelFilter() {final Vertex a = graph.addVertex();
        final Vertex b = graph.addVertex();
        final Vertex c = graph.addVertex();

        final String labelFriend = graphProvider.convertLabel("friend");
        final String labelHate = graphProvider.convertLabel("hate");

        final Edge aFriendB = a.addEdge(labelFriend, b);
        final Edge aFriendC = a.addEdge(labelFriend, c);
        final Edge aHateC = a.addEdge(labelHate, c);
        final Edge cHateA = c.addEdge(labelHate, a);
        final Edge cHateB = c.addEdge(labelHate, b);

        List<Edge> results = IteratorUtils.list(a.edges(Direction.OUT));
        assertEquals(3, results.size());
        assertTrue(results.contains(aFriendB));
        assertTrue(results.contains(aFriendC));
        assertTrue(results.contains(aHateC));

        results = IteratorUtils.list(a.edges(Direction.OUT, labelFriend));
        assertEquals(2, results.size());
        assertTrue(results.contains(aFriendB));
        assertTrue(results.contains(aFriendC));

        results = IteratorUtils.list(a.edges(Direction.OUT, labelHate));
        assertEquals(1, results.size());
        assertTrue(results.contains(aHateC));

        results = IteratorUtils.list(a.edges(Direction.IN, labelHate));
        assertEquals(1, results.size());
        assertTrue(results.contains(cHateA));

        results = IteratorUtils.list(a.edges(Direction.IN, labelFriend));
        assertEquals(0, results.size());

        results = IteratorUtils.list(b.edges(Direction.IN, labelHate));
        assertEquals(1, results.size());
        assertTrue(results.contains(cHateB));

        results = IteratorUtils.list(b.edges(Direction.IN, labelFriend));
        assertEquals(1, results.size());
        assertTrue(results.contains(aFriendB));
    }
Create a small {@link Graph} and ensure that counts of edges per vertex are correct.
gremlin-test/src/main/java/org/apache/tinkerpop/gremlin/structure/GraphTest.java