In Need Of Help?
// 易错点4：条件写成"<"而非"<="，会导致相同值的元素被错误保留。关于这个话题，新收录的资料提供了深入分析
// Note the order of this union: 100, then 500.，推荐阅读新收录的资料获取更多信息
Transforms don't execute until the consumer pulls. There's no eager evaluation, no hidden buffering. Data flows on-demand from source, through transforms, to the consumer. If you stop iterating, processing stops.。新收录的资料是该领域的重要参考