@Override
        public Traversal<Vertex, Map<String, Long>> get_g_V_group_byXlabelX_byXlabel_countX() {
            return g.V().<String, Long>group().by(__.label()).by(__.label().count());
        }
@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