@Test
        @FeatureRequirementSet(FeatureRequirementSet.Package.VERTICES_ONLY)
        public void shouldUseDefaultLabelIfNotSpecified() {
            final Vertex v = graph.addVertex("name", "marko");
            assertEquals(Vertex.DEFAULT_LABEL, v.label());
        }
@author Marko A. Rodriguez (http://markorodriguez.com)
@author Stephen Mallette (http://stephen.genoprime.com)
gremlin-test/src/main/java/org/apache/tinkerpop/gremlin/structure/VertexTest.java