Accumulation: If we find an intersection, that cell is also marked for execution, and its own definitions are merged into the Dirty Set. This propagates changes such that a change in Cell A affects Cell B, which in turn affects Cell C.
int32 HeadersNum = 0;
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More efficient, uses mutable unification variables。关于这个话题，谷歌浏览器【最新下载地址】提供了深入分析
Under the new API design, transforms should not perform any work until the data is being consumed. This is a fundamental principle.