let res = stack.join('');
明确需求，该买就买，买新不买旧。
。爱思助手下载最新版本对此有专业解读
"Birds of a Feather" by Billie Eilish (Episode 5)
Technically, a CRDT can be anything that follows the merging rules described below. This is a working definition; in practice, implementations in object-oriented languages will end up looking something like this. ↩
“真正的L4需依靠L2++城市NOA大规模量产积累数据。当L2++覆盖绝大部分场景，用户在边界外才接管，这种体验本身就符合L3的描述。” 地平线首席生态官徐健说。