async _setOpenedWithoutPropertyEffects(newOpened) {
      this.__blockSyncToOverlayCtrl = true;
      this.opened = newOpened;
      await this.updateComplete;
      this.__blockSyncToOverlayCtrl = false;
    }
When the opened state is changed by an Application Developer,cthe OverlayController is
requested to show/hide. It might happen that this request is not honoured
(intercepted in before-hide for instance), so that we need to sync the controller state
to this webcomponent again, preventing eternal loops.
@param {boolean} newOpened
@protected