VAE
https://github.com/pytorch/examples/blob/master/vae/main.py
https://github.com/atinghosh/VAE-pytorch/blob/master/VAE_CNN_Gaussianloss.py
https://medium.com/@schatty/vae-careful-walkthrough-5d01e7dbf1ab
https://github.com/wiseodd/generative-models
https://wiseodd.github.io/techblog/2017/01/24/vae-pytorch/
https://ratsgo.github.io/generative%20model/2018/01/27/VAE/
https://towardsdatascience.com/understanding-variational-autoencoders-vaes-f70510919f73