async getPublicKeys(req, res) {
        try {
            const jwks = await this._tokenService.getPublicKeys();
            res.json(jwks);
        } catch (err) {
            const error = new errors.InternalServerError({
                message: tpl(messages.keyStoreError),
                err
            });
            logging.error(error);
            throw error;
        }
    }
@param {import('express').Request} req 
@param {import('express').Response} res