namespace CAD_DBS = Autodesk::AutoCAD::DatabaseServices;
CAD_DBS::BlockTable^ bt = safe_cast<CAD_DBS::BlockTable^>(tr->GetObject(db->BlockTableId,
CAD_DBS::OpenMode::ForRead));
CAD_DBS::BlockTableRecord ^btr=safe_cast<CAD_DBS::BlockTableRecord^>(tr->GetObject(bt->item(CAD_DBS::BlockTableRecord::ModelSpace),
CAD_DBS::OpenMode::ForRead));