def _check_fit_called(self):
        """Checks if the scorer has been fitted before calling its `score()` function."""
        if not self._fit_called:
            raise_log(
                ValueError(
                    f"The Scorer {str(self)} has not been fitted yet. Call `fit()` first."
                ),
                logger=logger,
            )
Checks if the scorer has been fitted before calling its `score()` function.
darts/ad/scorers/scorers.py