public FormViewModel(ObservableCollection<string> packges, Form form = null)
 {
     FormObject = form ?? new Form
                              {
                                  UsedPackages = new ObservableCollection<string>(),
                                  UnusedPackages = new ObservableCollection<string>(packges)
                              };
 }
 public FormViewModel(Form form = null)
 {
     FormObject = form ?? new Form();
 }