private static Item parseItem(boolean isDigit, String buf) {
        return isDigit ? new IntegerItem(buf) : new StringItem(buf, false);
    }
Represents a version list item. This class is used both for the global item list and for sub-lists (which start
with '-(number)' in the version specification).
plugin/src/main/java/com/mcxiaoke/packer/ng/StringVersion.java