pasteText method
Paste text from Clipboard.
If there is currently a selection, it will be replaced.
If and only if cause
is SelectionChangedCause.toolbar, the toolbar
will be hidden and the current selection will be scrolled into view.
Implementation
@override
Future<void> pasteText(SelectionChangedCause cause) {
// TOD: implement pasteText
throw UnimplementedError();
}