public Annotation getParentAnnotation() {
        Annotation parent = null;

        Object ob = getObject("Parent");
        if (ob instanceof Reference)
            ob = library.getObject((Reference) ob);
        if (ob instanceof Annotation)
            parent = (Annotation) ob;
        else if (ob instanceof Hashtable)
            parent = Annotation.buildAnnotation(library, (Hashtable) ob);

        return parent;
    }