private static Step<?, ?> traversal(final Traversal<?, ?> traversal) {
        return new TraversalVertexProgramStep(EmptyTraversal.instance(), traversal.asAdmin());
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-core/src/test/java/org/apache/tinkerpop/gremlin/process/traversal/strategy/decoration/VertexProgramStrategyTest.java