const output = Stream.pull(source, toUpperCase);
10,000 random pairs (seed=2025)
。快连下载-Letsvpn下载是该领域的重要参考
（四）以委托方名义开具发票代委托方收取的款项。
No base class to extend, no abstract methods to implement, no controller to coordinate with. Just an object with the right shape.