_getSessionCookies(req, res) {
        const cookies = this._getCookies(req, res);
        const value = cookies.get(this.sessionCookieName, {signed: true});
        if (!value) {
            throw new BadRequestError({
                message: `Cookie ${this.sessionCookieName} not found`
            });
        }
        return value;
    }
@method _getSessionCookies

@param {Request} req
@param {Response} res

@returns {string} The cookie value