How to download the item list from estimate/quote?

@operator

Please help:

I'm developping an interface to download Transaction->Estimate/Quote records from NetSuite to a thrid party processing system. However, I can get all data but the item list, the item list is empty but I know there are item data in actual.

My operation is as below:

  private void SearchBaseIO()
        {
             this.Login(true);

            TransactionSearch transactionSearch = new TransactionSearch();
            TransactionSearchBasic transactionSearchBase = new TransactionSearchBasic();

            SearchDateField lastModifyDate = null;

           
            SearchStringField tranId = new SearchStringField();
            tranId.@operator = SearchStringFieldOperator.contains;
            tranId.operatorSpecified = true;
            tranId.searchValue = "51589";
            transactionSearchBase.tranId = tranId;

            string transType = InitializeRefType.estimate.ToString();
            SearchEnumMultiSelectField type = new SearchEnumMultiSelectField();
            type.@operator = SearchEnumMultiSelectFieldOperator.anyOf;
            type.operatorSpecified = true;
            type.searchValue = transType.Split(',');