[SalesForce] Error creating CPQ – SBQQ__QuoteLine__c Object

I am trying to test a controller that I have written which queries SBQQ__QuoteLine__c objects. I am running into an error which is preventing me from inserting the object during the @TestSetup method.

I believe it is because I am missing a field on the SBQQ__QuoteLine__c object, but I cannot figure it out because I am unable to see the code in the managed package. Has anyone run into this before?

Error

System.DmlException: Insert failed. First exception on row 0; first
error: CANNOT_INSERT_UPDATE_ACTIVATE_ENTITY, SBQQ.QuoteLineAfter:
execution of AfterInsert

caused by: System.NullPointerException: Attempt to de-reference a null
object

Class.SBQQ.QuoteLineVO.getCostScheduleId: line 1729, column 1
Class.SBQQ.QuoteVO.getDiscountScheduleIds: line 251, column 1
Class.SBQQ.QuoteCalculator.initDiscountSchedules: line 83, column 1
Class.SBQQ.QuoteCalculator.: line 47, column 1
Class.SBQQ.QuoteCalculatorFactory.newQuoteCalculator: line 33, column
1 Class.SBQQ.QuoteCalculatorFactory.newQuoteCalculator: line 26,
column 1 Class.SBQQ.QuoteService.calculate: line 324, column 1
Class.SBQQ.QuoteService.calculate: line 261, column 1
Class.SBQQ.QuoteService.calculate: line 257, column 1
Class.SBQQ.QuoteService.calculateAndSynch: line 204, column 1
Class.SBQQ.QuoteService.processLineTriggerAfter: line 1158, column 1
Trigger.SBQQ.QuoteLineAfter: line 12, column 1: []

Test Class

The 'insert' on the quote lines objects is what is throwing the error listed above.

@isTest 
private class QuoteLineListCtrl_Test {

    private static Integer QUOTE_LINE_ITEM_COUNT = 50;

    @TestSetup
    private static void setup(){
        Account account = (Account) SmartFactory.createSObject('Account');
        insert account;

        Contact contact = (Contact) SmartFactory.createSObject('Contact');
        insert contact;

        Id pricebookId = Test.getStandardPricebookId();

        Opportunity opportunity = (Opportunity) SmartFactory.createSObject('Opportunity');
        opportunity.AccountId = account.Id;
        insert opportunity;

        opportunity.Pricebook2Id = pricebookId;
        update opportunity;

        Product2 product = (Product2) SmartFactory.createSObject('Product2');
        insert product;

        SBQQ__Cost__c cost = new SBQQ__Cost__c();
        cost.SBQQ__Product__c = product.Id;
        cost.SBQQ__UnitCost__c = 100;
        insert cost;

        PricebookEntry pricebookEntry = new PricebookEntry();
        pricebookEntry.Pricebook2Id = pricebookId;
        pricebookEntry.Product2Id = product.Id;
        pricebookEntry.IsActive = true;
        pricebookEntry.UnitPrice = 100;
        insert pricebookEntry;

        SBQQ__Quote__c quote = new SBQQ__Quote__c();
        quote.SBQQ__Account__c = account.Id;
        quote.SBQQ__Opportunity2__c = opportunity.Id;
        quote.SBQQ__PrimaryContact__c = contact.Id;
        quote.SBQQ__Primary__c = TRUE;
        quote.Final_Signature_Date__c = Date.today();
        insert quote;

        List<SBQQ__QuoteLine__c> quoteLineItems = new List<SBQQ__QuoteLine__c>();
        for(Integer i = 0; i < QUOTE_LINE_ITEM_COUNT; i++){
            SBQQ__QuoteLine__c quoteLineItem = new SBQQ__QuoteLine__c();
            quoteLineItem.SBQQ__Quote__c = quote.Id;
            quoteLineItem.SBQQ__Quantity__c = 1;
            quoteLineItem.SBQQ__RegularPrice__c = 100;
            quoteLineItem.SBQQ__CustomerPrice__c = 50;
            quoteLineItem.SBQQ__Cost__c = cost.Id;

            quoteLineItems.add(quoteLineItem);
        }

        insert quoteLineItems;
    }

    @isTest
    private static void queryQuoteLines() {

        SBQQ__Quote__c quote = [SELECT Id FROM SBQQ__Quote__c LIMIT 1];

        Test.startTest();

            List<SBQQ__QuoteLine__c> quoteLineItems = QuoteLineListCtrl.queryQuoteLines(quote.Id);

        Test.stopTest();

        System.assertEquals(null, quoteLineItems);
        System.assertEquals(QUOTE_LINE_ITEM_COUNT, quoteLineItems.size());
    }
}