reactor-core/src/main/java/reactor/core/scheduler/Schedulers.java
public static void shutdownNow() {
		CachedScheduler oldElastic = CACHED_ELASTIC.getAndSet(null);
		CachedScheduler oldParallel = CACHED_PARALLEL.getAndSet(null);
		CachedScheduler oldSingle = CACHED_SINGLE.getAndSet(null);

		if (oldElastic != null) oldElastic._dispose();
		if (oldParallel != null) oldParallel._dispose();
		if (oldSingle != null) oldSingle._dispose();
	}
public static void shutdownNow() {
		CachedScheduler oldElastic = CACHED_ELASTIC.getAndSet(null);
		CachedScheduler oldParallel = CACHED_PARALLEL.getAndSet(null);
		CachedScheduler oldSingle = CACHED_SINGLE.getAndSet(null);

		if (oldElastic != null) oldElastic._dispose();
		if (oldParallel != null) oldParallel._dispose();
		if (oldSingle != null) oldSingle._dispose();
	}
Clear any cached {@link Scheduler} and call dispose on them.