public static boolean isLocalStarGraph(final Traversal.Admin<?, ?> traversal) {
        return 'x' != isLocalStarGraph(traversal, 'v');
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
@author Stephen Mallette (http://stephen.genoprime.com)
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/util/TraversalHelper.java