Draw facet label onto the axes.

        This function will only draw labels if they are needed.

        Parameters
        ----------
        layout_info : dict-like
            facet information
        ax : axes
            Axes to label

def draw_label(self, layout_info, ax):
        """
        Draw facet label onto the axes.

        This function will only draw labels if they are needed.

        Parameters
        ----------
        layout_info : dict-like
            facet information
        ax : axes
            Axes to label
        """
        label_info = layout_info[list(self.vars)]
        label_info._meta = {'dimension': 'cols'}
        label_info = self.labeller(label_info)
        self.draw_strip_text(label_info, 'top', ax)