@Override
    @NonNull
    public Set<Attribute<UpdateCenter, ?>> describe() {
        return new HashSet<>(
                Collections.singletonList(new MultivaluedAttribute<UpdateCenter, UpdateSite>("sites", UpdateSite.class)
                        .getter(UpdateCenter::getSiteList)
                        .setter((target, value) -> target.getSites().replaceBy(value))));
    }
TODO would  not be required if UpdateCenter had a DataBoundConstructor
plugin/src/main/java/io/jenkins/plugins/casc/core/UpdateCenterConfigurator.java