public StringList getLexicalEnumeration() {
        if (fLexicalEnumeration == null){
            if (fEnumeration == null)
                return StringListImpl.EMPTY_LIST;
            int size = fEnumeration.size();
            String[] strs = new String[size];
            for (int i = 0; i < size; i++)
                strs[i] = fEnumeration.elementAt(i).toString();
            fLexicalEnumeration = new StringListImpl(strs, size);
        }
        return fLexicalEnumeration;
    }