If you don't accumulate small steps, you can't reach thousands of miles
if you don't accumulate small streams, you can't become a river
https://github.com/tensorflow/models/tree/master/official/nlp/albert
https://github.com/google-research/bert
https://github.com/google-research/bert/blob/master/run_pretraining.py
https://tfhub.dev/s?q=bert