@Override
        public Traversal<Vertex, Long> get_g_V_hasLabelXsongsX_matchXa_name_b__a_performances_cX_selectXb_cX_count() {
            return g.V().hasLabel("song").match(
                    __.as("a").values("name").as("b"),
                    __.as("a").values("performances").as("c")
            ).select("b", "c").count();
        }
@author Joshua Shinavier (http://fortytwo.net)
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-test/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/map/MatchTest.java