private static <R> void test(R expectedResult, final Traversal<?, R> traversal) throws Exception {
        test(null, expectedResult, traversal);
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
spark-gremlin/src/test/java/org/apache/tinkerpop/gremlin/spark/process/computer/traversal/strategy/optimization/SparkInterceptorStrategyTest.java