public AnnotationTypeDoc[] annotationTypes() {
        ListBuffer<AnnotationTypeDocImpl> ret =
            new ListBuffer<AnnotationTypeDocImpl>();
        for (ClassDocImpl c : getClasses(true)) {
            if (c.isAnnotationType()) {
                ret.append((AnnotationTypeDocImpl)c);
            }
        }
        return ret.toArray(new AnnotationTypeDocImpl[ret.length()]);
    }