class Restrictions {

    protected static Integer[] range(int from, int to) {
        if (from > to) {
            throw new IllegalArgumentException("from must be <= to (" + from
                    + "," + to + ")");
        }
        int n = to - from + 1;
        Integer[] range = new Integer[n];
        for (int i = 0; i < n; i++) {
            range[i] = from + i;
        }
        return range;
    }

    private  Restrictions();

}