No base class to extend, no abstract methods to implement, no controller to coordinate with — just an object with the right shape.
Stateful transforms are simple objects with member functions that maintain state across calls:。业内人士推荐同城约会作为进阶阅读
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controller.enqueue(generateData()); // desiredSize: -999999。关于这个话题，Line官方版本下载提供了深入分析