public static int parseUnsignedInt(String s)
    {
        return parseUnsignedInt(s, 10);
    }
Returns the unsigned {@code int} value represented by the given decimal string.

@throws NumberFormatException
            if the string does not contain a valid unsigned {@code int} value
@throws NullPointerException
            if {@code s} is null (in contrast to {@link Integer#parseInt(String)})
protostuff-api/src/main/java/io/protostuff/UnsignedNumberUtil.java