public function deleteBlacklist($domain, $number)
    {
        if (!$domain)
            throw new BadMethodCallException('Parameter $domain is missing.');
        if (!$number)
            throw new BadMethodCallException('Parameter $number is missing.');
        try {
            $r = $this->delete('sms/' . $domain . '/blacklists/' . $number)->send();
        } catch (\Exception $e) {
            throw new SmsException($e->getMessage(), $e->getCode(), $e);
        }
        return $r;
    }