public Collection<FieldDeclaration> getFields() {
        ArrayList<FieldDeclaration> res = new ArrayList<FieldDeclaration>();
        for (Symbol s : getMembers(true)) {
            if (s.kind == Kinds.VAR) {
                res.add(env.declMaker.getFieldDeclaration((VarSymbol) s));
            }
        }
        return res;
    }