added_tokens.json

{
  "<causal>": 50260,
  "<fitm_result>": 50259,
  "<fitm_start>": 50257,
  "<mlm_end>": 50263,
  "<mlm_start>": 50261,
  "<multiple_tok_mask>": 50258,
  "<single_tok_mask>": 50262
}