public function assign(string $domain, string $ip)
    {
        Assert::stringNotEmpty($domain);
        Assert::ip($ip);

        $params = [
            'id' => $ip,
        ];

        $response = $this->httpPost(sprintf('/v3/domains/%s/ips', $domain), $params);

        return $this->hydrateResponse($response, UpdateResponse::class);
    }