public static NodeBadge number(int n) {
        // TODO: consider constraints, e.g. 1 <= n <= 999
        return new NodeBadge(Status.INFO, false, Integer.toString(n), null);
    }
@Test
    public void numberError() {
        badge = NodeBadge.number(Status.ERROR, NUM);
        checkFields(badge, Status.ERROR, false, NUM_STR, null);
    }