    def predict_loop(self, model, eval_dataloader, output_file="result.pkl"):
        """refactored from line 144:
        https://github.com/DmZhukov/CrossTask/blob/master/train.py
        """
        ctx = 0
        model.eval()
        model = model.to(ctx)
        # this is not a loss but just compute neg_log_prob.
        Y_pred = []
        Y_true = []
        with torch.no_grad():
            for batch in eval_dataloader:
                self(batch, model, Y_pred, Y_true)
        return self.finalize(Y_pred, Y_true, output_file)
refactored from line 144:
https://github.com/DmZhukov/CrossTask/blob/master/train.py
examples/MMPT/mmpt/evaluators/predictor.py