setContents method
Implementation
@experimental
void setContents(
Delta delta, {
ChangeSource changeSource = ChangeSource.local,
}) {
final newDocument = Document.fromDelta(delta);
final change = DocChange(_document.toDelta(), delta, changeSource);
newDocument.documentChangeObserver.add(change);
newDocument.history.handleDocChange(change);
_document = newDocument;
notifyListeners();
}