public function sendMultiple(array $invoiceSources, $forceSend, $dryRun, array &$log)
    {
        $this->getTranslator()->add(new ResultTranslations());
        $errorLogged = false;
        $success = true;
        $time_limit = ini_get('max_execution_time');
        foreach ($invoiceSources as $invoiceSource) {
            // Try to keep the script running, but note that other systems
            // involved, like the (Apache) web server, may have their own
            // time-out. Use @ to prevent messages like "Warning:
            // set_time_limit(): Cannot set max execution time limit due to
            // system policy in ...".
            if (!@set_time_limit($time_limit) && !$errorLogged) {
                $this->getLog()->warning('InvoiceManager::sendMultiple(): could not set time limit.');
                $errorLogged = true;
            }

            $result = $this->getInvoiceResult('InvoiceManager::sendMultiple()');
            $result = $this->createAndSend($invoiceSource, $result, $forceSend, $dryRun);
            $success = $success && !$result->hasError();
            $this->getLog()->notice($this->getSendResultLogText($invoiceSource, $result));
            $log[$invoiceSource->getId()] = $this->getSendResultLogText($invoiceSource, $result,Result::AddReqResp_Never);
        }
        return $success;
    }