code: public SchedulerStats stats() {
  		int activeThreads = threadPoolExecutor.getActiveCount();
  		return SchedulerStats.of(ThreadPoolStats.of(
  			threadPoolExecutor.getCorePoolSize(),
  			threadPoolExecutor.getMaximumPoolSize(),
  			activeThreads,
  			threadPoolExecutor.getPoolSize() - activeThreads,
  			threadPoolExecutor.getLargestPoolSize()
  		));
  	}
docs: Fetch statistics about the current {@code Scheduler}