private void LoadFile(string fileName)
 {
     // see if we already have this file open.
     if (!m_OpenFiles.Contains((vm) => vm.FilePath == fileName))
     {
         DataModels.CompiledFile newFile = BinaryFileLoader.LoadFile(fileName);
         var newVm = new CompiledFileViewModel(newFile);
         m_OpenFiles.Add(newVm);
         ActiveFileIndex = m_OpenFiles.Count - 1;
     }
     else
     {
         ActiveFileIndex = m_OpenFiles.IndexOf(vm => vm.FileName == fileName);
     }
 }
        private void SaveFile(string fileName)
        {
            CompiledFileViewModel targetVm = m_OpenFiles[ActiveFileIndex];

            targetVm.SaveFileAs(fileName);
        }