def _extract_model_creation_params(self):
        """extracts immutable model creation parameters from `ModelMeta` and deletes reference."""
        model_params = copy.deepcopy(self._model_call)
        del self.__class__._model_call
        return model_params
extracts immutable model creation parameters from `ModelMeta` and deletes reference.
darts/models/forecasting/forecasting_model.py