public int getRequiredIntValue(String valueDescription) throws OptionsException {
        String value = getRequiredValue(valueDescription);
        try {
            return Integer.parseInt(value);
        } catch (NumberFormatException e) {
            throw new OptionsException(
                    valueDescription + " (" + lastOptionOriginalForm
                            + ") must be a decimal number: " + value);
        }
    }
Returns the value of the current numeric option, throwing an exception if the value is
missing or is not numeric.
cli/src/main/java/com/mcxiaoke/packer/cli/Options.java