private static void square(List<Double> numbers) {
        if (numbers.size() < 2) {
            for (int i = 0; i < numbers.size(); i++) {
                numbers.set(i, Math.pow(numbers.get(i), 2));
            }
            return;
        }
        int middle = numbers.size() / 2;

        square(numbers.subList(0, middle));
        square(numbers.subList(middle, numbers.size()));
    }