Understanding Dynamic Block Copy for IJCAD 2021 PRO

public static void Main()
    {
        string filePath=@"C:\sample.dwg"; // Dynamic Block File

        Document document = Application.DocumentManager.MdiActiveDocument;
        using(Transaction transaction= document.Database.TransactionManager.StartTransaction())
        using(var blockTable=transaction.GetObject( document.Database.BlockTableId, OpenMode.ForRead) as BlockTable)
        using (var blockTableRecord=transaction.GetObject( document.Database.CurrentSpaceId, OpenMode.ForWrite) as BlockTableRecord)
        using(var symbolBlock=new BlockTableRecord())
        using(var symbolDwgDatabase=newDatabase(false, true))
        {
            symbolBlock.Name = "testName";
            blockTable.UpgradeOpen();
            ObjectId symbolBlockId=blockTable.Add(symbolBlock);
            transaction.AddNewlyCreatedDBObject(symbolBlock, true);

            symbolDwgDatabase.ReadDwgFile(filePath, FileOpenMode.OpenForReadAndAllShare, false, string.Empty);
            symbolDwgDatabase.CloseInput(true);
            using(Transaction symbolDwgTransaction=symbolDwgDatabase.TransactionManager.StartTransaction())
            using(var symbolDwgBlockTable=symbolDwgTransaction.GetObject(symbolDwgDatabase.BlockTableId, OpenMode.ForRead) as BlockTable)
            using(var symbolDwgBlock=symbolDwgTransaction.GetObject(symbolDwgBlockTable["sampleBlock", OpenMode.ForRead) as BlockTableRecord)
            {
                var symbolDwgIds = new ObjectIdCollection();
                foreach (var objectId in symbolDwgBlock)
                {
                    symbolDwgIds.Add(objectId);
                }
                using(varicMap=newIdMapping())
                {
                    // DeepCloneObjects Does Not Reflect on Drawings
                    // symbolDwgDatabase.DeepCloneObjects (symbolDwgIds, symbolBlockId, icMap, false);
                    symbolDwgDatabase.WblockCloneObjects(symbolDwgIds, symbolBlockId,icMap, DuplicateRecordCloning.Replace, false);
                }
                symbolDwgTransaction.Commit();
            }

            using(var blockReference=new BlockReference(Point3d.Origin, symbolBlockId)
            {
                blockReference.UpgradeOpen();
                blockReference.Layer="0";
                blockTableRecord.AppendEntity (blockReference);
                transaction.AddNewlyCreatedDBObject(blockReference, true);
            }
            transaction.Commit();
        }
    }