public function send(MessageInterface $message, $skipErrors = true) {
        if (count($message->getRecipient()) > self::MAX_RECIPIENS) {
            throw new ConfigurationException('Too many recipiens. For SerwerSms gateway limit is ' . self::MAX_RECIPIENS);
        }

        $client = $this->getClient();

        // details must be always true
        $extraParams = $this->getParam('extra');
        if (!isset($extraParams['details']) || $extraParams['details'] === false) {
            $extraParams['details'] = true;
        }

        try {
            $response = $client->messages->sendSms(
                $message->getRecipients(),
                $message->getText(),
                $this->getParam('sender'),
                $extraParams
            );

            if ((int)$response->unsent > 0) {
                foreach ($response->items as $item) {
                    // @see http://dev.serwersms.pl/https-api-v2/wysylanie-wiadomosci-sms-o-jednakowej-tresci
                    if ($item->status === 'unsent') {
                        $this->addError(new SendingError($item->phone, $item->error_code, $item->error_message . 'id:' . $item->id));
                        if (!$skipErrors) {
                            throw new \RuntimeException($item->error_message, $item->error_code);
                        }
                    }
                }
            }
        }
        catch (Exception $e) {
            $this->addError(new SendingError('', $e->getCode(), $e->getMessage()));
            if (!$skipErrors) {
                throw new \RuntimeException($e->getMessage());
            }
        }
        return $this->getErrors()->count() === 0;
    }