提升代码可维护性和跨平台一致性，这样业务逻辑代码可以保持简洁统一，Android 和 iOS 主工程都不需要额外干预。
"Any day in his life can turn out like that," he said. "It can be good bits, and then it can be awful bits and aggressive bits and upsetting bits. And that's just what the Tourette's does. It's nasty."
，详情可参考heLLoword翻译官方下载
材质：皮肤，决定了外观（是金属的、塑料的，还是半透明的）。
// drop-oldest: Discard old data to make room