Nord\Lumen\Cors\CorsService::createResponse PHP Method

    protected function createResponse(Request $request, Response $response)
    {
        $origin = $request->headers->get('Origin');
        $response->headers->set('Access-Control-Allow-Origin', $origin);
        $vary = $request->headers->has('Vary') ? $request->headers->get('Vary') . ', Origin' : 'Origin';
        $response->headers->set('Vary', $vary);
        if ($this->allowCredentials) {
            $response->headers->set('Access-Control-Allow-Credentials', 'true');
        }
        if ($this->exposeHeaders) {
            $response->headers->set('Access-Control-Expose-Headers', implode(', ', $this->exposeHeaders));
        }
        return $response;
    }