public function importSubscribers(
        $groupId,
        $subscribers,
        $options = [
            'resubscribe' => false,
            'autoresponders' => false
        ]
    ) {
        $endpoint = $this->endpoint . '/' . $groupId . '/subscribers/import';

        $response = $this->restClient->post($endpoint, array_merge(['subscribers' => $subscribers], $options));

        return $response['body'];
    }