def _plot_cov_selection(
        importance: pd.DataFrame,
        title: str = "Variable importance",
        ax: Optional[matplotlib.axes.Axes] = None,
    ):
        """Plots the variable importance of the TFT model.

        Parameters
        ----------
        importance
            The encoder / decoder importance.
        title
            The title of the plot.
        ax
            Optionally, an axis to plot on. Otherwise, will create and plot on a new axis.
        """
        if ax is None:
            _, ax = plt.subplots()
        ax.barh(importance.columns.tolist(), importance.values[0].tolist())
        ax.set_title(title)
        ax.set_ylabel("Variable", fontsize=12)
        ax.set_xlabel("Variable importance in %")
        return ax
Plots the variable importance of the TFT model.

        Parameters
        ----------
        importance
            The encoder / decoder importance.
        title
            The title of the plot.
        ax
            Optionally, an axis to plot on. Otherwise, will create and plot on a new axis.
        
darts/explainability/tft_explainer.py