@Override
    public GraphTraversalSource traversal(final Graph graph) {
        return RANDOM.nextBoolean() ?
                graph.traversal().withComputer(Computer.compute(SparkGraphComputer.class).workers(RANDOM.nextInt(AVAILABLE_PROCESSORS) + 1)) :
                graph.traversal().withComputer();
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
@author Stephen Mallette (http://stephen.genoprime.com)
spark-gremlin/src/test/java/org/apache/tinkerpop/gremlin/spark/process/computer/SparkHadoopGraphProvider.java