data files:
  wiki.train.tokens.berttok.pkl
  wiki.test.tokens.berttok.pkl
  wiki.valid.tokens.berttok.pkl

These files are tokenised and pickled 

from transformers import BertTokenizer
tokenizer = BertTokenizer.from_pretrained('bert-base-uncased')

orignial download from: 
  https://dax-assets-dev.s3.us-south.cloud-object-storage.appdomain.cloud/dax-wikitext-103/1.0.0/wikitext-103.tar.gz

  - wiki.text.tokens
  - wiki.train.tokens
  - wiki.valid.tokens
