public function buildFeedRuleSet() : RuleSet
    {
        $ruleSet = $this->buildBaseRuleSet();
        $ruleSet
            ->add(new LinkNode())
            ->add(new PublicId('id'))
            ->add(new Language('lang'))
            ->add($this->getModifiedSinceRule('updated'))
        ;

        return $ruleSet;
    }