private function serializeAnswers(Paper $paper, array $options = [])
    {
        // We need to inject the hints available in the structure
        $options['hints'] = [];
        $decoded = json_decode($paper->getStructure(), true);

        foreach ($decoded['steps'] as $step) {
            foreach ($step['items'] as $item) {
                if (1 === preg_match('#^application\/x\.[^/]+\+json$#', $item['type'])) {
                    foreach ($item['hints'] as $hint) {
                        $options['hints'][$hint['id']] = $hint;
                    }
                }
            }
        }

        return array_map(function (Answer $answer) use ($options) {
            return $this->answerSerializer->serialize($answer, $options);
        }, $paper->getAnswers()->toArray());
    }