title: What is the alternative in Harmony OS for Nullable and NonNull annotations?
body: <p>There are many arguments in my code which can take the value null. It would be helpful if there is a @Nullable and @NonNull annotation like the ones offered in Android via <a href="https://developer.android.com/jetpack/androidx/releases/annotation" rel="nofollow noreferrer">Annotation</a>.</p>
  <p>Is there an alternative available in Harmony OS?</p>