/// <summary>
        /// Generates a signed "object" JWT.
        /// 1 REST call is made to pre-insert class.
        /// If this JWT only contains 1 object, usually isn't too long; can be used in Android intents/redirects.
        /// </summary>
        /// <param name="verticalType"> pass type to created</param>
        /// <param name="classId">the unique identifier for the class</param>
        /// <param name="objectId">the unique identifier for the object</param>
        /// <returns></returns>
        public string makeObjectJwt(VerticalType verticalType, string classId, string objectId)
        {
            ResourceDefinitions resourceDefinitions = ResourceDefinitions.getInstance();
            RestMethods         restMethods         = RestMethods.getInstance();
            // create JWT to put objects and class into JSON Web Token (JWT) format for Google Pay API for Passes
            Jwt googlePassJwt = new Jwt();

            // get class, object definitions, insert class (check in Merchant center GUI: https://pay.google.com/gp/m/issuer/list)
            try
            {
                switch (verticalType)
                {
                case VerticalType.OFFER:
                    OfferClass  offerClass  = resourceDefinitions.makeOfferClassResource(classId);
                    OfferObject offerObject = resourceDefinitions.makeOfferObjectResource(objectId, classId);
                    System.Console.WriteLine("\nMaking REST call to insert class");
                    OfferClass classResponse = restMethods.insertOfferClass(offerClass);
                    System.Console.WriteLine("\nMaking REST call to get object to see if it exists.");
                    OfferObject objectResponse = restMethods.getOfferObject(objectId);
                    // check responses
                    if (!(classResponse is null))
                    {
                        System.Console.WriteLine($"classId: {classId} inserted.");
                    }
                    else
                    {
                        System.Console.WriteLine($"classId: {classId} insertion failed. See above Server Response for more information.");
                    }
                    if (!(objectResponse is null))
                    {
                        System.Console.WriteLine($"objectId: {objectId} already exists.");
                    }
                    if (!(objectResponse is null) && objectResponse.ClassId != offerObject.ClassId)
                    {
                        System.Console.WriteLine($"the classId of inserted object is ({objectResponse.ClassId}). " +
                                                 $"It does not match the target classId ({offerObject.ClassId}). The saved object will not " +
                                                 "have the class properties you expect.");
                    }
                    // need to add only object because class was pre-inserted
                    googlePassJwt.addOfferObject(offerObject);
                    break;

                case VerticalType.LOYALTY:
                    LoyaltyClass  loyaltyClass  = resourceDefinitions.makeLoyaltyClassResource(classId);
                    LoyaltyObject loyaltyObject = resourceDefinitions.makeLoyaltyObjectResource(objectId, classId);
                    System.Console.WriteLine("\nMaking REST call to insert class");
                    LoyaltyClass loyaltyClassResponse = restMethods.insertLoyaltyClass(loyaltyClass);
                    System.Console.WriteLine("\nMaking REST call to get object to see if it exists.");
                    LoyaltyObject loyaltyObjectResponse = restMethods.getLoyaltyObject(objectId);
                    // check responses
                    if (!(loyaltyClassResponse is null))
                    {
                        System.Console.WriteLine($"classId: {classId} inserted.");
                    }
        /// <summary>
        /// Generates a signed "fat" JWT.
        /// No REST calls made.
        /// Use fat JWT in JS web button.
        /// Fat JWT is too long to be used in Android intents.
        /// Possibly might break in redirects.
        /// </summary>
        /// <param name="verticalType"> pass type to created</param>
        /// <param name="classId">the unique identifier for the class</param>
        /// <param name="objectId">the unique identifier for the object</param>
        /// <returns></returns>
        public string makeFatJwt(VerticalType verticalType, string classId, string objectId)
        {
            ResourceDefinitions resourceDefinitions = ResourceDefinitions.getInstance();
            RestMethods         restMethods         = RestMethods.getInstance();
            // create JWT to put objects and class into JSON Web Token (JWT) format for Google Pay API for Passes
            Jwt googlePassJwt = new Jwt();

            // get class definition, object definition and see if Ids exist. for a fat JWT, first time a user hits the save button, the class and object are inserted
            try
            {
                switch (verticalType)
                {
                case VerticalType.OFFER:
                    OfferClass  offerClass  = resourceDefinitions.makeOfferClassResource(classId);
                    OfferObject offerObject = resourceDefinitions.makeOfferObjectResource(objectId, classId);
                    System.Console.WriteLine("\nMaking REST call to get class and object to see if they exist.");
                    OfferClass  classResponse  = restMethods.getOfferClass(classId);
                    OfferObject objectResponse = restMethods.getOfferObject(objectId);
                    // check responses
                    if (!(classResponse is null))
                    {
                        System.Console.WriteLine($"classId: {classId} already exists.");
                    }
                    if (!(objectResponse is null))
                    {
                        System.Console.WriteLine($"objectId: {objectId} already exists.");
                    }
                    if (!(classResponse is null) && objectResponse.ClassId != offerObject.ClassId)
                    {
                        System.Console.WriteLine($"the classId of inserted object is ({objectResponse.ClassId}). " +
                                                 $"It does not match the target classId ({offerObject.ClassId}). The saved object will not " +
                                                 "have the class properties you expect.");
                    }
                    // need to add both class and object resource definitions into JWT because no REST calls made to pre-insert
                    googlePassJwt.addOfferClass(offerClass);
                    googlePassJwt.addOfferObject(offerObject);
                    break;

                case VerticalType.LOYALTY:
                    LoyaltyClass  loyaltyClass  = resourceDefinitions.makeLoyaltyClassResource(classId);
                    LoyaltyObject loyaltyObject = resourceDefinitions.makeLoyaltyObjectResource(objectId, classId);
                    System.Console.WriteLine("\nMaking REST call to get class and object to see if they exist.");
                    LoyaltyClass  loyaltyClassResponse  = restMethods.getLoyaltyClass(classId);
                    LoyaltyObject loyaltyObjectResponse = restMethods.getLoyaltyObject(objectId);
                    // check responses
                    if (!(loyaltyClassResponse is null))
                    {
                        System.Console.WriteLine($"classId: {classId} already exists.");
                    }
                    if (!(loyaltyObjectResponse is null))
                    {
                        System.Console.WriteLine($"objectId: {objectId} already exists.");
                    }
                    if (!(loyaltyClassResponse is null) && loyaltyObjectResponse.ClassId != loyaltyObject.ClassId)
                    {
                        System.Console.WriteLine($"the classId of inserted object is ({loyaltyObjectResponse.ClassId}). " +
                                                 $"It does not match the target classId ({loyaltyObject.ClassId}). The saved object will not " +
                                                 "have the class properties you expect.");
                    }
                    // need to add both class and object resource definitions into JWT because no REST calls made to pre-insert
                    googlePassJwt.addLoyaltyClass(loyaltyClass);
                    googlePassJwt.addLoyaltyObject(loyaltyObject);
                    break;

                case VerticalType.EVENTTICKET:
                    EventTicketClass  eventTicketClass  = resourceDefinitions.makeEventTicketClassResource(classId);
                    EventTicketObject eventTicketObject = resourceDefinitions.makeEventTicketObjectResource(objectId, classId);
                    System.Console.WriteLine("\nMaking REST call to get class and object to see if they exist.");
                    EventTicketClass  eventTicketClassResponse  = restMethods.getEventTicketClass(classId);
                    EventTicketObject eventTicketObjectResponse = restMethods.getEventTicketObject(objectId);
                    // check responses
                    if (!(eventTicketClassResponse is null))
                    {
                        System.Console.WriteLine($"classId: {classId} already exists.");
                    }
                    if (!(eventTicketObjectResponse is null))
                    {
                        System.Console.WriteLine($"objectId: {objectId} already exists.");
                    }
                    if (!(eventTicketClassResponse is null) && eventTicketObjectResponse.ClassId != eventTicketObject.ClassId)
                    {
                        System.Console.WriteLine($"the classId of inserted object is ({eventTicketObjectResponse.ClassId}). " +
                                                 $"It does not match the target classId ({eventTicketObject.ClassId}). The saved object will not " +
                                                 "have the class properties you expect.");
                    }
                    // need to add both class and object resource definitions into JWT because no REST calls made to pre-insert
                    googlePassJwt.addEventTicketClass(eventTicketClass);
                    googlePassJwt.addEventTicketObject(eventTicketObject);
                    break;

                case VerticalType.FLIGHT:
                    FlightClass  flightClass  = resourceDefinitions.makeFlightClassResource(classId);
                    FlightObject flightObject = resourceDefinitions.makeFlightObjectResource(objectId, classId);
                    System.Console.WriteLine("\nMaking REST call to get class and object to see if they exist.");
                    FlightClass  flightClassResponse  = restMethods.getFlightClass(classId);
                    FlightObject flightObjectResponse = restMethods.getFlightObject(objectId);
                    // check responses
                    if (!(flightClassResponse is null))
                    {
                        System.Console.WriteLine($"classId: {classId} already exists.");
                    }
                    if (!(flightObjectResponse is null))
                    {
                        System.Console.WriteLine($"objectId: {objectId} already exists.");
                    }
                    if (!(flightClassResponse is null) && flightObjectResponse.ClassId != flightObject.ClassId)
                    {
                        System.Console.WriteLine($"the classId of inserted object is ({flightObjectResponse.ClassId}). " +
                                                 $"It does not match the target classId ({flightObject.ClassId}). The saved object will not " +
                                                 "have the class properties you expect.");
                    }
                    // need to add both class and object resource definitions into JWT because no REST calls made to pre-insert
                    googlePassJwt.addFlightClass(flightClass);
                    googlePassJwt.addFlightObject(flightObject);
                    break;

                case VerticalType.GIFTCARD:
                    GiftCardClass  giftCardClass  = resourceDefinitions.makeGiftCardClassResource(classId);
                    GiftCardObject giftCardObject = resourceDefinitions.makeGiftCardObjectResource(objectId, classId);
                    System.Console.WriteLine("\nMaking REST call to get class and object to see if they exist.");
                    GiftCardClass  giftCardClassResponse  = restMethods.getGiftCardClass(classId);
                    GiftCardObject giftCardObjectResponse = restMethods.getGiftCardObject(objectId);
                    // check responses
                    if (!(giftCardClassResponse is null))
                    {
                        System.Console.WriteLine($"classId: {classId} already exists.");
                    }
                    if (!(giftCardObjectResponse is null))
                    {
                        System.Console.WriteLine($"objectId: {objectId} already exists.");
                    }
                    if (!(giftCardClassResponse is null) && giftCardObjectResponse.ClassId != giftCardObject.ClassId)
                    {
                        System.Console.WriteLine($"the classId of inserted object is ({giftCardObjectResponse.ClassId}). " +
                                                 $"It does not match the target classId ({giftCardObject.ClassId}). The saved object will not " +
                                                 "have the class properties you expect.");
                    }
                    // need to add both class and object resource definitions into JWT because no REST calls made to pre-insert
                    googlePassJwt.addGiftCardClass(giftCardClass);
                    googlePassJwt.addGiftCardObject(giftCardObject);
                    break;

                case VerticalType.TRANSIT:
                    TransitClass  transitClass  = resourceDefinitions.makeTransitClassResource(classId);
                    TransitObject transitObject = resourceDefinitions.makeTransitObjectResource(objectId, classId);
                    System.Console.WriteLine("\nMaking REST call to get class and object to see if they exist.");
                    TransitClass  transitClassResponse  = restMethods.getTransitClass(classId);
                    TransitObject transitObjectResponse = restMethods.getTransitObject(objectId);
                    // check responses
                    if (!(transitClassResponse is null))
                    {
                        System.Console.WriteLine($"classId: {classId} already exists.");
                    }
                    if (!(transitObjectResponse is null))
                    {
                        System.Console.WriteLine($"objectId: {objectId} already exists.");
                    }
                    if (!(transitClassResponse is null) && transitObjectResponse.ClassId != transitObject.ClassId)
                    {
                        System.Console.WriteLine($"the classId of inserted object is ({transitObjectResponse.ClassId}). " +
                                                 $"It does not match the target classId ({transitObject.ClassId}). The saved object will not " +
                                                 "have the class properties you expect.");
                    }
                    // need to add both class and object resource definitions into JWT because no REST calls made to pre-insert
                    googlePassJwt.addTransitClass(transitClass);
                    googlePassJwt.addTransitObject(transitObject);
                    break;
                }
                // return "fat" JWT. Try putting it into JS web button
                // note button needs to be rendered in local web server who's domain matches the ORIGINS
                // defined in the JWT. See https://developers.google.com/pay/passes/reference/s2w-reference
                return(googlePassJwt.generateSignedJwt());
            }
            catch (System.Exception e)
            {
                System.Console.WriteLine(e.Message);
                return(null);
            }
        }