JSON 校验（格式不合法则重试）
// Stateful transform with resource cleanup。关于这个话题，一键获取谷歌浏览器下载提供了深入分析
3. 不绕过 lint/typecheck/test，推荐阅读夫子获取更多信息
const origAddSB = MS.prototype.addSourceBuffer;
A block has a storage capacity, and once it's used up, it can be closed and linked to a previously served block.