destroy method
Implementation
@override
void destroy() {
if (_destroyed) return;
_destroyed = true;
_destroyCtrl.add(null);
_destroyCtrl.close();
// destroy 会真正地通知原生端销毁原生广告数据
AdseyeLogger.debug(
'[NativeAd] Destroying native ad data for requestId: $requestId',
);
super.destroy(); // 调用 BaseAd 的 destroy
}