src/transformers/models/bart/tokenization_bart_fast.py/BartTokenizerFast/build_inputs_with_special_tokens
class BartTokenizerFast:    def build_inputs_with_special_tokens(self, token_ids_0, token_ids_1=None):
        output = [self.bos_token_id] + token_ids_0 + [self.eos_token_id]
        if token_ids_1 is None:
            return output

        return output + [self.eos_token_id] + token_ids_1 + [self.eos_token_id]