def _check_univariate(s: TimeSeries):
            """Checks if `anomalies` contains only univariate series, which
            is required if any of the scorers returns a univariate score.
            """
            if self.is_univariate and not s.width == 1:
                raise_log(
                    ValueError(
                        f"Scorer {str(self)} will return a univariate anomaly score series (width=1). "
                        f"Found a multivariate `anomalies`. "
                        f"The evaluation of the accuracy cannot be computed between the two series."
                    ),
                    logger=logger,
                )
Checks if `anomalies` contains only univariate series, which
            is required if any of the scorers returns a univariate score.
            
darts/ad/scorers/scorers.py