/// <summary>
        /// Note: Handles null storefront with system default message
        /// </summary>
        /// <param name="storeFront"></param>
        /// <param name="code"></param>
        /// <param name="uri"></param>
        /// <returns></returns>
        public static string AddPhoneNumberMessage(StoreFront storeFront, string code, Uri uri)
        {
            string messageBody = "Your security code is: " + code + " \n";
            if (storeFront != null)
            {
                messageBody += "\n" + storeFront.OutgoingMessageSignature();
            }
            messageBody += "\n\n" + Settings.IdentityTwoFactorSignature;

            return messageBody;
        }