逐行源码阅读中文笔记。
blog解读与复现：https://blog.csdn.net/qq_39388410/article/details/85160996
原paper： Bayesian Personalized Ranking(BPR) is a learning algorithm for collaborative filtering first introduced in: BPR: Bayesian Personalized Ranking from Implicit Feedback. Steffen Rendle, Christoph Freudenthaler, Zeno Gantner and Lars Schmidt-Thieme, Proc. UAI 2009.