}
    }

    private static <T> Supplier<T> asSupplier(Callable<T> supplier) {
        return () -> {
            try {
                return supplier.call();
            } catch (Exception e) {
                uncheckedThrow(e);
                return null;
            }
        };
    }

            // invokeAll method, so that whenever the method is called,
            // the pool core size will be incremented before submitting
            // all the tasks, then the thread will block waiting for all
            // those subtasks to finish.
            // This ensures the number of running workers is no more than
            // the defined parallism, while making sure the pool will not