@Override
    public GraphComputer getGraphComputer(final Graph graph) {
        return RANDOM.nextBoolean() ?
                graph.compute().workers(RANDOM.nextInt(AVAILABLE_PROCESSORS) + 1) :
                graph.compute(SparkGraphComputer.class);
    }
@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