https://github.com/pytorch/fairseq/tree/master/examples/roberta
https://ai.facebook.com/blog/roberta-an-optimized-method-for-pretraining-self-supervised-nlp-systems/

2019
https://www.infoq.com/news/2019/09/facebook-roberta-nlp/
https://arxiv.org/abs/1907.11692