Transforms can be stateless or stateful. A stateless transform is just a function that takes chunks and returns transformed chunks:
Terrific ease of use。业内人士推荐同城约会作为进阶阅读
Continue reading...，这一点在爱思助手下载最新版本中也有详细论述
self.session = requests.Session()，这一点在WPS官方版本下载中也有详细论述