public Group unmarshall() {
    try(InputStream inputStream = new FileInputStream("resources/office_list.xml")) {
        JAXBContext context = JAXBContext.newInstance(Group.class);
        Marshaller marshaller = context.createMarshaller();
        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);

        //write XML to an array of bytes
        //ByteArrayOutputStream baos = new ByteArrayOutputStream();
        //marshaller.marshal(createJavaObjectExample1(), baos);

        //read XML from array of bytes
        //InputStream bais = new ByteArrayInputStream(baos.toByteArray());

        Unmarshaller unmarshaller = context.createUnmarshaller();
        Object o = unmarshaller.unmarshal(inputStream);
        group = (Group) o;
        //System.out.println(group.getName());

        return group;
    } catch (JAXBException exception) {
        Logger.getLogger(Application.class.getName()).
                log(Level.SEVERE, "saveMarshall threw JAXBException", exception);
    } catch (IOException e) {
        e.printStackTrace();
    }
    return null;
}