Controller/JWKSetController.php
public function getAction($_format)
    {
        if ('json' === $_format) {
            $value = json_encode($this->jwkset);
            $ct = 'application/jwk-set+json; charset=UTF-8';
        } else {
            $value = json_encode($this->jwkset->toPEM());
            $ct = 'application/json; charset=UTF-8';
        }

        return new Response($value, Response::HTTP_OK, ['content-type' => $ct]);
    }
public function getAction($_format)
    {
        if ('json' === $_format) {
            $value = json_encode($this->jwkset);
            $ct = 'application/jwk-set+json; charset=UTF-8';
        } else {
            $value = json_encode($this->jwkset->toPEM());
            $ct = 'application/json; charset=UTF-8';
        }

        return new Response($value, Response::HTTP_OK, ['content-type' => $ct]);
    }
@param string $_format

@return \Symfony\Component\HttpFoundation\Response