def compute_features(self, model, x):
        """
        Compute features from prev model and current model
        """
        prev_model = self.prev_model
        assert prev_model is not None
        model.eval()
        prev_model.eval()

        features = model.get_features(x)
        prev_features = prev_model.get_features(x)

        return features, prev_features

        Compute features from prev model and current model
        
avalanche/training/plugins/lfl.py