@Override
        public Traversal<Vertex, List<Double>> get_g_V_mapXbothE_weight_foldX_order_byXsumXlocalX_descX() {
            return g.V().map(__.bothE().<Double>values("weight").fold()).order().by(__.sum(Scope.local), Order.desc);
        }
@author Marko A. Rodriguez (http://markorodriguez.com)
@author Stephen Mallette (http://stephen.genoprime.com)
gremlin-test/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/map/OrderTest.java