@Override
        public Traversal<Vertex, Double> get_g_V_asXaX_outXknowsX_asXbX_mathXa_plus_bX_byXageX() {
            return g.V().as("a").out("knows").as("b").math("a + b").by("age");
        }
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-test/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/map/MathTest.java