def unwrap_model(self, model: Module) -> Module:
        """
        Unwrap a model.

        :param model: A model to be unwrapped.
        :return: The unwrapped model.
        """
        if isinstance(model, DistributedDataParallel):
            return model.module

        return model

        Unwrap a model.

        :param model: A model to be unwrapped.
        :return: The unwrapped model.
        
avalanche/distributed/distributed_helper.py