private void shutdownAndAwaitTermination(ExecutorService executorService) {
        executorService.shutdown(); // Disable new tasks from being submitted
        try {
            // Wait a while for existing tasks to terminate
            if (!executorService.awaitTermination(5, TimeUnit.SECONDS)) {
                executorService.shutdownNow(); // Cancel currently executing tasks
                // Wait a while for tasks to respond to being cancelled
                if (!executorService.awaitTermination(5, TimeUnit.SECONDS)) {
                    System.err.println("ExecutorService did not terminate");
                }
            }
        } catch (InterruptedException ie) {
            // (Re-)Cancel if current thread also interrupted
            executorService.shutdownNow();
            // Preserve interrupt status
            Thread.currentThread().interrupt();
        }
    }