src/Service/CacheKeyBuilder/EtagHasher.php
public function hash(Response $response)
    {
        $params = [
            $response->getLastModified()->format(\DateTime::ISO8601),
        ];

        // add cookies to ETag
        if ($this->request_stack->getMasterRequest()) {
            $params[] = http_build_query($this->request_stack->getMasterRequest()->cookies->all());
        }

        return hash($this->algorithm, implode(self::ETAG_SEPARATOR, $params));
    }
public function hash(Response $response)
    {
        $params = [
            $response->getLastModified()->format(\DateTime::ISO8601),
        ];

        // add cookies to ETag
        if ($this->request_stack->getMasterRequest()) {
            $params[] = http_build_query($this->request_stack->getMasterRequest()->cookies->all());
        }

        return hash($this->algorithm, implode(self::ETAG_SEPARATOR, $params));
    }
@param Response $response

@return string