Not yet implemented (major areas)
历史的接力棒已交到手中，唯有保持清醒头脑、秉持务实作风、扛起担当之责，方能跑出无愧于时代的优异答卷。
，更多细节参见PG官网
err(_) = return none,
Streaming server-side rendering (SSR) is a particularly painful case. A typical SSR stream might render thousands of small HTML fragments, each passing through the streams machinery: