message: Hid tabs only when the scene is current
  iOS calls each scene in stack asking whether tabs are hidden. I guess once one hides then all future hides but it's a per scene setting with the navigation router
diff: - (BOOL)hidesBottomBarWhenPushed
  {
  - return _view.hidesTabs;
  + return [self.navigationController.visibleViewController isEqual:self] && _view.hidesTabs;
  }
  - (void)dealloc
  