def _clean(self) -> Self:
        """Returns a cleaned instance of the model by removing the training series and covariates."""

        # a shallow copy is enough since we are only interested in removing pointers to the training data
        cleaned_model = copy.copy(self)
        cleaned_model.training_series = None
        cleaned_model.past_covariate_series = None
        cleaned_model.future_covariate_series = None
        cleaned_model.static_covariates = None
        return cleaned_model
Returns a cleaned instance of the model by removing the training series and covariates.
darts/models/forecasting/forecasting_model.py