@Override
        public Traversal<Vertex, List<Integer>> get_g_V_aggregateXxX_byXvaluesXageX_isXgtX29XXX_capXxX() {
            return g.V().aggregate("x").by(__.values("age").is(P.gt(29))).cap("x");
        }
@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/sideEffect/AggregateTest.java