src/transformers/utils/notebook.py/NotebookProgressCallback/on_prediction_step
class NotebookProgressCallback:    def on_prediction_step(self, args, state, control, eval_dataloader=None, **kwargs):
        if not has_length(eval_dataloader):
            return
        if self.prediction_bar is None:
            if self.training_tracker is not None:
                self.prediction_bar = self.training_tracker.add_child(len(eval_dataloader))
            else:
                self.prediction_bar = NotebookProgressBar(len(eval_dataloader))
            self.prediction_bar.update(1)
        else:
            self.prediction_bar.update(self.prediction_bar.value + 1)