public function serialize(BooleanQuestion $question, array $options = [])
    {
        // Serializes choices
        $choices = $this->serializeChoices($question, $options);

        if (in_array(Transfer::SHUFFLE_ANSWERS, $options)) {
            shuffle($choices);
        }

        $serialized = ['choices' => $choices];

        if (in_array(Transfer::INCLUDE_SOLUTIONS, $options)) {
            $serialized['solutions'] = $this->serializeSolutions($question);
        }

        return $serialized;
    }