@SuppressWarnings("unchecked")
    public static int[] getSavableVersions(Class<? extends Savable> clazz) throws IOException {
        ArrayList<Integer> versionList = new ArrayList<>();
        Class superclass = clazz;
        do {
            versionList.add(getSavableVersion(superclass));
            superclass = superclass.getSuperclass();
        } while (superclass != null && SavableClassUtil.isImplementingSavable(superclass));

        int[] versions = new int[versionList.size()];
        for (int i = 0; i < versionList.size(); i++) {
            versions[i] = versionList.get(i);
        }
        return versions;
    }
A private constructor to inhibit instantiation of this class.
jme3-core/src/main/java/com/jme3/export/SavableClassUtil.java