Revise paste Class for Save/Load warcraft 3 models with MD...

static class ModelSaverLoader
 {
     public static CModel? Load(string FromFileName)
     {
         CModel TemporaryModel = new CModel();
         string extension = System.IO.Path.GetExtension(FromFileName).ToLower();
         if (extension == ".mdx")
         {
             try
             {
                 using (var Stream = new System.IO.FileStream(FromFileName, System.IO.FileMode.Open, System.IO.FileAccess.Read))
                 {
                     var ModelFormat = new MdxLib.ModelFormats.CMdx();
                     ModelFormat.Load(FromFileName, Stream, TemporaryModel);
                 }
             }
             catch (Exception ex)
             {
                 MessageBox.Show(ex.ToString(), $"Exception occured while trying to open {FromFileName}");
                 // CurrentModel = new CModel();
                 return null;
             }
         }
         if (extension == ".mdl")
         {
             try
             {
                 using (var Stream = new System.IO.FileStream(FromFileName, System.IO.FileMode.Open, System.IO.FileAccess.Read))
                 {
                     var ModelFormat = new MdxLib.ModelFormats.CMdl();
                     ModelFormat.Load(FromFileName, Stream, TemporaryModel);
                 }
             }
             catch (Exception ex)
             {
                 MessageBox.Show(ex.ToString(), $"Exception occured while trying to open {FromFileName}");
                 //  CurrentModel = new CModel();
                 return null;
             }
         }
         return TemporaryModel;
     }
     internal static void Save(CModel model, string file)
     {
         if (file.Length == 0) { MessageBox.Show("Empty save path"); return; }
         if (
            (System.IO.Path.GetExtension(file) == ".mdx" ||
             System.IO.Path.GetExtension(file) == ".mdl") == false
             ) { MessageBox.Show("Invalid extension"); return; }
         if (model == null) { MessageBox.Show("Null model"); return; }
         if (System.IO.Path.GetExtension(file).ToLower() == ".mdl")
         {
             string ToFileName = file;
             using (var Stream = new System.IO.FileStream(ToFileName, System.IO.FileMode.Create, System.IO.FileAccess.Write))
             {
                 var ModelFormat = new MdxLib.ModelFormats.CMdl();
                 ModelFormat.Save(ToFileName, Stream, model);
             }
             FileCleaner.CleanFile(ToFileName);
         }
         if (System.IO.Path.GetExtension(file).ToLower() == ".mdx")
         {
             string ToFileName = file;
             using (var Stream = new System.IO.FileStream(ToFileName, System.IO.FileMode.Create, System.IO.FileAccess.Write))
             {
                 var ModelFormat = new MdxLib.ModelFormats.CMdx();
                 ModelFormat.Save(ToFileName, Stream, model);
             }
         }
     }
 }