Laravel\Lumen\Concerns\RoutesRequests::mergeMiddlewareGroup PHP Method

    protected function mergeMiddlewareGroup($action)
    {
        if (isset($this->groupAttributes['middleware'])) {
            if (isset($action['middleware'])) {
                $action['middleware'] = array_merge($this->groupAttributes['middleware'], $action['middleware']);
            } else {
                $action['middleware'] = $this->groupAttributes['middleware'];
            }
        }
        return $action;
    }