WDL 学习教程
推荐系统+WDL 教学视频: https://www.bilibili.com/video/av29905315/
WDL 模型介绍: https://blog.csdn.net/google19890102/article/details/78171283
WDL 代码解释: https://chromium.googlesource.com/external/github.com/tensorflow/tensorflow/+/r0.10/tensorflow/g3doc/tutorials/wide_and_deep/index.md
Google 的官方 WDL 案例：
https://github.com/tensorflow/models/tree/master/official/r1/wide_deep
install requirement: https://github.com/tensorflow/models/tree/master/official
feature columns 详细说明：
https://tensorflow.google.cn/tutorials/structured_data/feature_columns?hl=zh-cn
feature columns 案例说明：
http://xudongyang.coding.me/tensorflow-feature-columns/
Dataset 详细说明：
https://tensorflow.google.cn/versions/r1.14/api_docs/python/tf/data/Dataset
WDL saved_model froze问题，我没有实现
https://github.com/tensorflow/tensorflow/issues/8665
https://github.com/formath/tensorflow-predictor-cpp/blob/master/python/freeze_graph.py