@Override
        public Traversal<Vertex, Double> get_g_V_aggregateXaX_byXageX_meanXlocalX() {
            return g.V().aggregate("a").by("age").cap("a").mean(Scope.local);
        }
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-test/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/map/MeanTest.java