@Test
    @FeatureRequirementSet(FeatureRequirementSet.Package.SIMPLE)
    public void shouldNotConstructNewWithSomethingAlreadyReferenced() {
        final Vertex v = graph.addVertex();
        final VertexProperty vp = v.property(VertexProperty.Cardinality.single, "test", "this");
        final ReferenceVertexProperty dvp = ReferenceFactory.detach(vp);
        assertEquals("test", dvp.label());
        assertEquals("test", dvp.key());
        assertEquals("this", dvp.value());
        assertSame(dvp, ReferenceFactory.detach(dvp));
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-test/src/main/java/org/apache/tinkerpop/gremlin/structure/util/reference/ReferenceVertexPropertyTest.java