__onChildCheckedChanged(cfgOrEvent) {
      const { target } = cfgOrEvent;
      if (cfgOrEvent.stopPropagation) {
        cfgOrEvent.stopPropagation();
      }
      if (target.checked && !this.multipleChoice) {
        this._uncheckChildren(target);
      }
    }
@param {Event & { target: LionOption }} cfgOrEvent
@private