src/transformers/models/bart/modeling_bart.py/BartForConditionalGeneration/prepare_decoder_input_ids_from_labels
class BartForConditionalGeneration:    def prepare_decoder_input_ids_from_labels(self, labels: torch.Tensor):
        return shift_tokens_right(labels, self.config.pad_token_id, self.config.decoder_start_token_id)