@Test
    public void shouldNotShutdownExecutorServicesSuppliedToGremlinExecutor() throws Exception {
        final ScheduledExecutorService service = Executors.newScheduledThreadPool(4, testingThreadFactory);
        final GremlinExecutor gremlinExecutor = GremlinExecutor.build()
                .executorService(service)
                .scheduledExecutorService(service).create();

        gremlinExecutor.close();
        assertFalse(service.isShutdown());
        service.shutdown();
        service.awaitTermination(30000, TimeUnit.MILLISECONDS);
    }
Temporary "useless" plugin definition to force GremlinExecutor to use GremlinScriptEngineManager - will be
removed when the old functionality of ScriptEngines is removed.
gremlin-groovy/src/test/java/org/apache/tinkerpop/gremlin/groovy/engine/GremlinExecutorTest.java