def after_training_exp(
        self, strategy, num_workers: int = 0, shuffle: bool = True, **kwargs
    ):
        """
        Set untrained_solver boolean to False after (the first) experience,
        in order to start training with replay data from the second experience.
        """
        self.untrained_solver = False

        Set untrained_solver boolean to False after (the first) experience,
        in order to start training with replay data from the second experience.
        
avalanche/training/plugins/generative_replay.py