public ObjectList getActualEnumeration() {
        if (fActualEnumeration == null) {
            fActualEnumeration = new AbstractObjectList() {
                public int getLength() {
                    return (fEnumeration != null) ? fEnumeration.size() : 0;
                }
                public boolean contains(Object item) {
                    return (fEnumeration != null && fEnumeration.contains(item));
                }
                public Object item(int index) {
                    if (index < 0 || index >= getLength()) {
                        return null;
                    }
                    return fEnumeration.elementAt(index);
                }
            };
        }
        return fActualEnumeration;
    }