repeat(sb, '*', DEFAULT_MAX_SIZE);
        return sb.toString();
    }

    public static List<String> format(String... lines) {
        int size = DEFAULT_MAX_SIZE;
        int remainder = size - 4; // 4 chars = 2 box_char + 2 spaces
        List<String> result = new ArrayList<>();
        StringBuilder sb = new StringBuilder(size);
        // first line
        sb.setLength(0);
        repeat(sb, BOX_CHAR, size);