public EditorTextEnteringEvent(DocumentViewModel viewModel, TextEditor editor, TextCompositionEventArgs args)
 {
     ViewModel = viewModel;
     Editor = editor;
     Args = args;
 }
 public EditorPreviewKeyDownEvent(DocumentViewModel viewModel, TextEditor editor, KeyEventArgs args)
 {
     ViewModel = viewModel;
     Editor = editor;
     Args = args;
 }