addCookieIfExists = (cookieName) => {
        if (isString(cookieName)) {
            let name = getSingleCookie(cookieName);
            name !== '' && allCookies.push(name);
        } else {
            allCookies.push(...getAllCookies(cookieName));
        }
    }
Add cookie to allCookies array if it exists
@param {string | RegExp} cookieName