@Override
        public Traversal<Vertex, Double> get_g_V_hasXageX_valueMap_mathXit_plus_itXbyXselectXageX_unfoldXX() {
            // https://issues.apache.org/jira/browse/TINKERPOP-1979 - should work in OLAP
            return g.V().has("age").valueMap().math("_+_").by(select("age").unfold());
        }
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-test/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/map/MathTest.java