Zend\Expressive\Application::pipeRouteResultObserverMiddleware PHP Method

    public function pipeRouteResultObserverMiddleware()
    {
        if ($this->routeResultObserverMiddlewareIsRegistered) {
            return;
        }
        $this->pipe([$this, 'routeResultObserverMiddleware']);
        $this->routeResultObserverMiddlewareIsRegistered = true;
    }