public ExtGState getExtGState(String namedReference) {
        ExtGState gsState = null;
        if (extGStates != null) {
            Object attribute = library.getObject(extGStates, namedReference);
            if (attribute instanceof Hashtable) {
                gsState = new ExtGState(library, (Hashtable) attribute);
            } else if (attribute instanceof Reference) {
                gsState = new ExtGState(library,
                        (Hashtable) library.getObject(
                                (Reference) attribute));
            }
        }
        return gsState;

    }