XMPBox XMPBasicSchema setters don't work if already set

        DomXmpParser xmpParser = new DomXmpParser();
        xmpParser.setStrictParsing(false);
        InputStream is = meta.createInputStream();
        org.apache.xmpbox.XMPMetadata xmp = xmpParser.parse(is);
        is.close();
        XMPBasicSchema basic = xmp.getXMPBasicSchema();
        Calendar createDate = basic.getCreateDate();
        System.out.println(createDate);
        basic.setCreateDate(new GregorianCalendar());
        createDate = basic.getCreateDate();
        System.out.println(createDate);