@Override
        public Traversal<Vertex, Map<Long, Collection<String>>> get_g_V_group_byXoutE_countX_byXnameX() {
            return g.V().<Long, Collection<String>>group().by(outE().count()).by("name");
        }
@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/GroupTest.java