public function getSender($domain, $sender)
    {
        if (!$domain)
            throw new BadMethodCallException('Parameter $domain is missing.');
        if (!$sender)
            throw new BadMethodCallException('Parameter $sender is missing.');
        $sender = urlencode($sender);
        try {
            $r = $this->get('sms/' . $domain . '/senders/' . $sender)->send();
        } catch (\Exception $e) {
            throw new SmsException($e->getMessage(), $e->getCode(), $e);
        }
        return $r->getBody(true);
    }