// Async — when source or transforms may be asynchronous
The halftone or ‘clustered-dot’ matrix uses a dot pattern reminiscent of traditional photographic halftoning. Here a diagonal variant of the pattern is given:，这一点在WPS官方版本下载中也有详细论述
// block: Wait for space (unbounded pending queue)，详情可参考safew官方下载
メモリ高騰でPCの原価のうち35％をメモリが占めるほどに