public void shutdownExecutorAndAwaitTermination(ExecutorService pool) {
        System.out.printf("!!!!!!!! Executor has shutdown - no more requests");
        pool.shutdown(); // Disable new tasks from being submitted
        try {
          // Wait a while for existing tasks to terminate
          if (!pool.awaitTermination(60, TimeUnit.SECONDS)) {
            pool.shutdownNow(); // Cancel currently executing tasks
            System.out.printf("!!!!!!!! Tasks running after 60 seconds have been cancelled");
            // Wait a while for tasks to respond to being cancelled
            if (!pool.awaitTermination(60, TimeUnit.SECONDS))
                System.err.println("Pool did not terminate");
          }
        } catch (InterruptedException ie) {
          // (Re-)Cancel if current thread also interrupted
          pool.shutdownNow();
          // Preserve interrupt status
          Thread.currentThread().interrupt();
        }
      }