@Override
        public Traversal<Vertex, Vertex> get_g_VX2X_inE_outV(final Object v2Id) {
            return g.V(v2Id).inE().outV();
        }
@author Marko A. Rodriguez (http://markorodriguez.com)
@author Stephen Mallette (http://stephen.genoprime.com)
@author Daniel Kuppitz (http://gremlin.guru)
gremlin-test/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/map/VertexTest.java