Psr7Middlewares\Middleware\SaveResponse::canSave PHP Method

    private function canSave(RequestInterface $request, ResponseInterface $response)
    {
        if ($request->getMethod() !== 'GET') {
            return false;
        }
        if ($response->getStatusCode() !== 200) {
            return false;
        }
        if (!$this->appendQuery && !empty($request->getUri()->getQuery())) {
            return false;
        }
        if ($response->hasHeader('location')) {
            return false;
        }
        $cacheControl = $response->getHeaderLine('Cache-Control');
        if ($cacheControl && (stripos($cacheControl, 'no-cache') !== false || stripos($cacheControl, 'no-store') !== false)) {
            return false;
        }
        return true;
    }