def first_values(self) -> np.ndarray:
        """
        First values of this potentially multivariate series.

        Returns
        -------
        np.ndarray
            The first values of every component of this deterministic time series
        """
        self._assert_deterministic()
        return self._xa.values[0, :, 0].copy()

        First values of this potentially multivariate series.

        Returns
        -------
        np.ndarray
            The first values of every component of this deterministic time series
        
darts/timeseries.py