code: private void hideUndoView(@NonNull final View view) {
          mCallback.getPrimaryView(view).setVisibility(View.VISIBLE);
          mCallback.getUndoView(view).setVisibility(View.GONE);
      }
docs: Sets the visibility of the primary {@link android.view.View} to {@link android.view.View#VISIBLE}, and that of the undo {@code View} to {@link android.view.View#GONE}.
  
  @param view the parent {@code View} which contains both primary and undo {@code View}s.