Google\Spreadsheet\CellFeed::insertBatch PHP Method

    public function insertBatch(BatchRequest $batchRequest)
    {
        $xml = $batchRequest->createRequestXml($this);
        $response = ServiceRequestFactory::getInstance()->addHeader("If-Match", "*")->post($this->getBatchUrl(), $xml->asXML());
        ServiceRequestFactory::getInstance()->removeHeader("If-Match");
        return new BatchResponse(new \SimpleXMLElement($response));
    }