@Override
    protected List<Traversal> getTraversals() {
        return Arrays.asList(
                __.out(),
                __.in(),
                __.both(),
                __.out("knows"),
                __.out("created"),
                __.out("knows", "created")
        );
    }
@author Daniel Kuppitz (http://gremlin.guru)
gremlin-core/src/test/java/org/apache/tinkerpop/gremlin/process/traversal/step/map/VertexStepTest.java