src/transformers/models/bigbird_pegasus/modeling_bigbird_pegasus.py/BigBirdPegasusForConditionalGeneration/prepare_decoder_input_ids_from_labels
class BigBirdPegasusForConditionalGeneration:    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)