@Test
    @FeatureRequirementSet(FeatureRequirementSet.Package.VERTICES_ONLY)
    public void shouldHashAndEqualCorrectly() {
        final Vertex v = graph.addVertex();
        final Set<Vertex> set = new HashSet<>();
        for (int i = 0; i < 100; i++) {
            set.add(ReferenceFactory.detach(v));
            set.add(v);
        }
        assertEquals(1, set.size());
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-test/src/main/java/org/apache/tinkerpop/gremlin/structure/util/reference/ReferenceVertexTest.java