explored some other intriguing opportunities, like the very first production
if (res === '') res = '0';
，更多细节参见Line官方版本下载
"Or consider pipeTo(). Each chunk passes through a full Promise chain: read, write, check backpressure, repeat. An {value, done} result object is allocated per read. Error propagation creates additional Promise branches.，详情可参考Line官方版本下载
Producer: Ben Ellman