private static String join(String sep, Object... lines) {
        StringBuilder sb = new StringBuilder();
        for (Object line : lines) {
            if (sb.length() > 0) {
                sb.append(sep);
            }
            sb.append(line);
        }
        return sb.toString();
    }
Sorts {@code OptionSpec} instances by their name in case-insensitive
alphabetic order. If an option has multiple names, the shortest name is used
for the sorting. Help options follow non-help options.
docs/genadoc.java