protected function errorResponse(ServerRequestInterface $request, ResponseInterface $response)
    {
        if (
            interface_exists(GlobalEnvironmentInterface::class, false) &&
            $response instanceof GlobalEnvironmentInterface &&
            $response->isStale()
        ) {
            $response = $response->revive();
        }

        $errorResponse = $response->withProtocolVersion($request->getProtocolVersion())->withStatus(500);
        $errorResponse->getBody()->write('An unexpected error occured');

        return $errorResponse;
    }