EDI Fabric .ToEDI() имеет пустые групповые поля

Я использую EDIFabric для создания обмена и одиночного сообщения. У меня очень простой формат, который мне нужно вывести в строку EDI x12. Мой код правильно заполняет обмен и группу (просматривая локальные переменные и коллекции), однако, когда я запускаю .ToEdi() для своего объекта обмена, я возвращаю пустые группы сообщений

Мой вывод:

"ISA*00*          *00*          *IS*SenderID       *IS*ReceiverID     *160809*1008*^*00501*000001ISA*0*P*:~GS*FA*GS_02_SenderCode*GS_03_ReceiverCode*21160809*1008*00001GS06*X*005010~ST~AK1~AK2~IK3~IK5~AK9~SE~GE*000001*00001GS06~IEA*00001*000001ISA~"

Пусто, когда не должно быть

ST~AK1~AK2~IK3~IK5~AK9~SE~GE

Класс создания

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using EdiFabric.Framework.Envelopes.X12;
using EdiFabric.Definitions.Hipaa_005010_999_X231;
using EdiFabric.Framework.Messages;
using EdiFabric.Framework.Envelopes;
namespace X12PayloadProcessing
{
    public class DS_M_999
    {
        private DS_M_999_Interchange _Interchange;
        private DS_M_999_Group _Group;

        private Message _EDI_Message;
        private S_ISA _EDI_ISA = new  S_ISA();
        private S_IEA _EDI_IEA = new S_IEA();
        public Interchange _EDI_Interchange = new Interchange();
        private S_GE _EDI_GE = new S_GE();
        private S_GS _EDI_GS = new S_GS();

        private Group _EDI_Group = new Group();
        private M_999 _EDI_999 = new M_999();
        private S_ST _EDI_ST = new S_ST();
        private S_SE _EDI_SE = new S_SE();
        private S_AK1 _EDI_AK1 = new S_AK1();
        private S_AK2 _EDI_AK2 = new S_AK2();
        private S_AK9 _EDI_AK9 = new S_AK9();
        private S_IK3 _EDI_IK3 = new S_IK3();
        private S_IK5 _EDI_IK5 = new S_IK5();

        private List<G_TS999_2000> _EDI_2000_List = new List<G_TS999_2000>();
        private G_TS999_2000 _EDI_2000 = new G_TS999_2000();

        private G_TS999_2100 _EDI_2100 = new G_TS999_2100();
        private List<G_TS999_2100> _EDI_2100_List = new List<G_TS999_2100>();



        public DS_M_999(DS_M_999_Group Group, DS_M_999_Interchange Interchange)
        {
            _Group = Group;
            _Interchange = Interchange;

            _EDI_Interchange.Groups = new List<Group>();

            _EDI_ISA.D_744_1 = _Interchange.ISA_01_Authorization.PadRight(2).Substring(0,2);
            _EDI_ISA.D_745_2 = _Interchange.ISA_02_AuthInfo.PadRight(10).Substring(0,10);
            _EDI_ISA.D_746_3 = _Interchange.ISA_03_SecurityQualifier.PadRight(2).Substring(0, 2);
            _EDI_ISA.D_747_4 = _Interchange.ISA_04_Password.PadRight(10).Substring(0, 10);
            _EDI_ISA.D_704_5 = _Interchange.ISA_05_SenderQualifier.PadRight(2).Substring(0, 2);
            _EDI_ISA.D_705_6 = _Interchange.ISA_06_SenderId.PadRight(15).Substring(0,15);
            _EDI_ISA.D_704_7 = _Interchange.ISA_07_ReceiverQualifier.PadRight(2).Substring(0, 2);
            _EDI_ISA.D_706_8 = _Interchange.ISA_08_ReceiverId.PadRight(15).Substring(0, 15);
            _EDI_ISA.D_373_9 = _Interchange.ISA_09_DateReceived.PadRight(6).Substring(0, 6);
            _EDI_ISA.D_337_10 = _Interchange.ISA_10_TimeRecieved.PadRight(4).Substring(0, 4);
            _EDI_ISA.D_726_11 = _Interchange.ISA_11_RepetitionSeparator.PadRight(1).Substring(0, 1);
            _EDI_ISA.D_703_12 = _Interchange.ISA_12_X12Version.PadRight(5).Substring(0, 5);
            _EDI_ISA.D_709_13 = _Interchange.ISA_13_UniqueNumberCounter.PadLeft(9,'0');
            _EDI_ISA.D_749_14 = _Interchange.ISA_14_AcknoledgementRequested;
            _EDI_ISA.D_748_15 = _Interchange.ISA_15_UsageIndicator;
            _EDI_ISA.D_701_16 = _Interchange.ISA_16_CompElementSeparator;

            _EDI_IEA.D_405_1 = _Interchange.IEA_01_FunctionalGroupCounter.PadLeft(5, '0');
            _EDI_IEA.D_709_2 = _Interchange.IEA_02_UniqueNumberCounter.PadLeft(9, '0');

            _EDI_Interchange.Iea = _EDI_IEA;
            _EDI_Interchange.Isa = _EDI_ISA;

            _EDI_GE.D_97_1 = _Interchange.GE_01_TransactionSetCounter.PadLeft(6, '0');
            _EDI_GE.D_28_2 = _Interchange.GE_02_UniqueNumberCounter.PadLeft(9, '0');
            _EDI_Group.Ge = _EDI_GE;

            _EDI_GS.D_479_1 = _Interchange.GS_01.PadRight(2).Substring(0, 2);
            _EDI_GS.D_142_2 = _Interchange.GS_02_SenderCode;
            _EDI_GS.D_124_3 = _Interchange.GS_03_ReceiverCode;
            _EDI_GS.D_29_4 = _Interchange.GS_04_DateReceived.PadRight(6).Substring(0, 8); //datetime.ToString("yyyyMMdd")
            _EDI_GS.D_30_5 = _Interchange.GS_05_TimeReceived.PadRight(4).Substring(0, 4); //datetime.ToString("HHmm")
            _EDI_GS.D_28_6 = _Interchange.GS_06_UniqueNumberCounter.PadLeft(9,'0');
            _EDI_GS.D_455_7 = _Interchange.GS_07_AgencyCode.PadRight(1).Substring(0, 1);
            _EDI_GS.D_480_8 = _Interchange.GS_08_X12Version.PadRight(6).Substring(0, 6);
            _EDI_Group.Gs = _EDI_GS;

            //Set ST Block
            _EDI_ST.D_ST01 = X12_ID_143.Item999; 
            _EDI_ST.D_ST02 = _Group.ST_02_TransactionSetCounter;
            _EDI_ST.D_ST03 = X12_ID_1705.Item005010X231A1;
            _EDI_999.S_ST = _EDI_ST;

            //Set AK1 Block
            _EDI_AK1.D_AK101 = _Group.AK_101_FunctionalIdentifier;
            _EDI_AK1.D_AK102 = _Group.AK_102_GroupControlNumber;
            _EDI_AK1.D_AK103 = _Group.AK_103_VersionIdentifier;
            _EDI_999.S_AK1 = _EDI_AK1;

            _EDI_AK2.D_AK201 = _Group.AK_201_TransactionSetIdentifier;
            _EDI_AK2.D_AK202 = _Group.AK_202_ControlNumber;
            _EDI_AK2.D_AK203 = _Group.AK_203_VersionIdentifier;
            _EDI_2000.S_AK2 = _EDI_AK2;


            //Set IK3 Block
            _EDI_IK3.D_IK301 = _Group.IK_301_MissingSegment;
            _EDI_IK3.D_IK302 = _Group.IK_302_PositionInTransactionSet;
            _EDI_IK3.D_IK304 = X12_ID_620.Item3; // _Group.IK_304_ErrorCode;
            _EDI_2100.S_IK3 = _EDI_IK3;


            //Set IK5 Block
            _EDI_IK5.D_IK501 = X12_ID_717.R;
            _EDI_IK5.D_IK502 = X12_ID_618.Item5;
            _EDI_2000.S_IK5 = _EDI_IK5;


            //Set Lists
            _EDI_2100_List.Add(_EDI_2100);
            _EDI_2000.G_TS999_2100 = _EDI_2100_List;

            _EDI_2000_List.Add(_EDI_2000);
            _EDI_999.G_TS999_2000 = _EDI_2000_List;

            //AK9 Block
            _EDI_AK9.D_AK901 = X12_ID_715.R;//_Group.AK_901_RejectIndicator;
            _EDI_AK9.D_AK902 = _Group.AK_902_NumberOfTransactionSets;
            _EDI_AK9.D_AK903 = _Group.AK_903_NumberOfTransactionSets;
            _EDI_AK9.D_AK904 = _Group.AK_904_NumberAccepted;

            _EDI_999.S_AK9 = _EDI_AK9;

            //SE Block
            _EDI_SE.D_SE01 = _Group.SE_01_SegmentCounter;
            _EDI_SE.D_SE02 = _Group.SE_02_TransactionSetCounter;

            _EDI_999.S_SE = _EDI_SE;

            _EDI_Message = new Message(_EDI_999);
            _EDI_Group.Messages.Add(new Message((object)_EDI_999));
            _EDI_Interchange.Groups.Add(_EDI_Group);        
        }

        public string GetEdiString()
        {
            var parsedXml = _EDI_Interchange.ToEdi();
            return string.Concat(parsedXml);
        }
    }



    public class DS_M_999_Interchange
    {
        public string ISA_01_Authorization { get; set; } //default 00
        public string ISA_02_AuthInfo { get; set; } //defualt ""
        public string ISA_03_SecurityQualifier { get; set; } //default 00
        public string ISA_04_Password { get; set; } //default ""

        //get from 270/276
        public string ISA_05_SenderQualifier { get; set; }
        public string ISA_06_SenderId { get; set; }
        public string ISA_07_ReceiverQualifier { get; set; }
        public string ISA_08_ReceiverId { get; set; }

        public string ISA_09_DateReceived { get; set; } //default YYMMDD
        public string ISA_10_TimeRecieved { get; set; } //default HHMM
        public string ISA_11_RepetitionSeparator { get; set; } //default ^
        public string ISA_12_X12Version { get; set; } //default 00501
        public string ISA_13_UniqueNumberCounter { get; set; } //will be generated by app
        public string ISA_14_AcknoledgementRequested { get; set; } //default 0
        public string ISA_15_UsageIndicator { get; set; } //default P
        public string ISA_16_CompElementSeparator { get; set; } //default :


        //Interchange GS 
        public string GS_01 { get; set; } //default FA

        //from 270/276
        public string GS_02_SenderCode { get; set; }
        public string GS_03_ReceiverCode { get; set; }

        public string GS_04_DateReceived { get; set; } //default CCYYMMDD
        public string GS_05_TimeReceived { get; set; } //default HHMM
        public string GS_06_UniqueNumberCounter { get; set; } //will be generated by app
        public string GS_07_AgencyCode { get; set; } //default "X"
        public string GS_08_X12Version { get; set; } //default 00501X231A1

        public string GE_01_TransactionSetCounter { get; set; } //number of transaction sets output typically 1
        public string GE_02_UniqueNumberCounter { get; set; } //same as GS06

        public string IEA_01_FunctionalGroupCounter { get; set; } //number of functional groups typically 1
        public string IEA_02_UniqueNumberCounter { get; set; } //same as ISA_13

        public DS_M_999_Interchange()
        {
            ISA_01_Authorization = "00";
            ISA_02_AuthInfo = "";
            ISA_03_SecurityQualifier = "00";
            ISA_04_Password = "";

            ISA_09_DateReceived = DateTime.Now.ToString("yyMMdd");
            ISA_10_TimeRecieved = DateTime.Now.ToString("HHMM");
            ISA_11_RepetitionSeparator = "^";
            ISA_12_X12Version = "005010";
            ISA_13_UniqueNumberCounter = "1ISA"; //Need to generate/track
            ISA_14_AcknoledgementRequested = "0";
            ISA_15_UsageIndicator = "P";
            ISA_16_CompElementSeparator = ":";

            GS_01 = "FA";

            GS_04_DateReceived = (DateTime.Now.Year / 100 + 1).ToString() + DateTime.Now.ToString("yyMMdd");
            GS_05_TimeReceived = DateTime.Now.ToString("HHMM");
            GS_06_UniqueNumberCounter = "1GS06"; //Need to generate/track
            GS_07_AgencyCode = "X";
            GS_08_X12Version = "005010X231A1";

            GE_01_TransactionSetCounter = "1";
            GE_02_UniqueNumberCounter = GS_06_UniqueNumberCounter;

            IEA_01_FunctionalGroupCounter = "1";
            IEA_02_UniqueNumberCounter = ISA_13_UniqueNumberCounter;           

        }

    }

    public class DS_M_999_Group
    {
        public string ST_01_TransactionSetIdentifier { get; set; } //default 999
        public string ST_02_TransactionSetCounter { get; set; } //will be generated by app startiing at 0001 (always 0001 in our instance)
        public string ST_03_X12Version { get; set; } //default 005010x231a1

        //from 270 /276
        public string AK_101_FunctionalIdentifier { get; set; }
        public string AK_102_GroupControlNumber { get; set; }
        public string AK_103_VersionIdentifier { get; set; }
        public string AK_201_TransactionSetIdentifier { get; set; }
        public string AK_202_ControlNumber { get; set; }
        public string AK_203_VersionIdentifier { get; set; }


        public string IK_301_MissingSegment { get; set; } //set from x12ParserHelper MissingFields
        public string IK_302_PositionInTransactionSet { get; set; } //need to figure this out by parsing incoming edi
        public string IK_304_ErrorCode { get; set; } //default 3

        public string IK_501_RejectIndicator { get; set; } //default R
        public string IK_502_RejectCode { get; set; } //default 5

        public string AK_901_RejectIndicator { get; set; } //default R

        //from 270/276
        public string AK_902_NumberOfTransactionSets { get; set; }
        public string AK_903_NumberOfTransactionSets { get; set; }

        public string AK_904_NumberAccepted { get; set; } //default 0

        public string SE_01_SegmentCounter { get; set; } //#of segments in tx set ST to SE 
        public string SE_02_TransactionSetCounter { get; set; } //same as ST02


        public DS_M_999_Group()
        {
            ST_01_TransactionSetIdentifier = "999";
            ST_02_TransactionSetCounter = "0001";            
            ST_03_X12Version = "005010X231A1";

            IK_304_ErrorCode = "3";
            IK_501_RejectIndicator = "R";
            IK_502_RejectCode = "5";

            AK_901_RejectIndicator = "R";
            AK_904_NumberAccepted = "0";

            SE_01_SegmentCounter = "1";
            SE_02_TransactionSetCounter = ST_02_TransactionSetCounter;

        }
    }
}

Тестовый класс:

using System;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using X12PayloadProcessing;

namespace X12PayloadProcessing.Tests
{
    [TestClass]
    public class DS_M_999_Tests
    {
        [TestMethod]
        public void DSM999_ToEdiStringShouldBeValid()
        {
            DS_M_999_Interchange Interchange = new DS_M_999_Interchange();
            Interchange.ISA_05_SenderQualifier = "ISA_05_SenderQualifier";
            Interchange.ISA_06_SenderId = "SenderID"; //15 space padded
            Interchange.ISA_07_ReceiverQualifier = "ISA_06_ReciverQualifier";
            Interchange.ISA_08_ReceiverId = "ReceiverID"; //15 space padded

            Interchange.GS_02_SenderCode = "GS_02_SenderCode";
            Interchange.GS_03_ReceiverCode = "GS_03_ReceiverCode";

            DS_M_999_Group Group = new DS_M_999_Group();
            Group.AK_101_FunctionalIdentifier = "AK_101_FunctionalIdentifier";
            Group.AK_102_GroupControlNumber = "AK_102_GroupControlNumber";
            Group.AK_103_VersionIdentifier = "AK_103_VersionIdentifier";
            Group.AK_201_TransactionSetIdentifier = "AK_201_TransactionSetIdentifier";
            Group.AK_202_ControlNumber = "AK_202_ControlNumber";
            Group.AK_203_VersionIdentifier = "AK_203_VersionIdentifier";
            Group.IK_301_MissingSegment = "IK_301_MissingSegment";
            Group.IK_302_PositionInTransactionSet = "IK_302_PositionInTransactionSet";

            Group.AK_902_NumberOfTransactionSets = "AK_902_NumberOfTransactionSets";
            Group.AK_903_NumberOfTransactionSets = "AK_903_NumberOfTransactionSets";

            DS_M_999 DS_M_999 = new DS_M_999(Group, Interchange);
            string ediString = DS_M_999.GetEdiString();
            var x = DS_M_999._EDI_Interchange.ToEdi();
            Assert.IsNotNull(ediString);


        }
    }
}

Тест пройдет как есть, но он не генерирует ожидаемый вывод EDI. Обевон Кенобе Пожалуйста, помогите, ваша единственная надежда.