public static void main(String[] args) throws IOException {
        int count_success = 0;
        int count_failure = 0;

        String bucket = getBucket();
        Collection<MyTask> collection = new ArrayList<MyTask>();

        for (int i = 0; i < NUM_TASKS; i++) {
            String uniqueKey = "file-" + UUID.randomUUID();
            MyTask myTask = new MyTask(bucket, uniqueKey);
            collection.add(myTask);
        }

        long startTime = System.currentTimeMillis();

        try {
            List<Future<Boolean>> list = executorPool.invokeAll(collection);
            for (Future<Boolean> fut : list) {
                if(fut.get()) {
                    count_success++;
                } else {
                    count_failure++;
                }
            }

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            long elapsedTime = (System.currentTimeMillis() - startTime);

            System.out.println("TOTAL SUCCESS - " + count_success);
            System.out.println("TOTAL FAILURE - " + count_failure);
            System.out.println("Total time - "    + elapsedTime + " ms");

            executorPool.shutdown();
        }
    }