src/Application/SimpleApplication.php
public function response(ResponseInterface $response = null) : ResponseInterface
    {
        if ($response){
            $this->response = $response;
        }
        if (!$this->response){
            $this->response = new NullResponse;
        }
        return $this->response;
    }
public function response(ResponseInterface $response = null) : ResponseInterface
    {
        if ($response){
            $this->response = $response;
        }
        if (!$this->response){
            $this->response = new NullResponse;
        }
        return $this->response;
    }
Set/get response

@param ResponseInterface $response

@return ResponseInterface