App\Models\Forum\FeatureVote::validateTopic PHP Method

    public function validateTopic()
    {
        if ($this->topic === null) {
            $this->validationErrors()->add('topic_id', 'required');
            return;
        }
        if (!$this->topic->isFeatureTopic()) {
            $this->validationErrors()->add('topic_id', '.not_feature_topic');
        }
    }