def add_legend_data(self, ax):
        if self.hue_names is not None:
            for rgb, label in zip(self.colors, self.hue_names):
                ax.scatter([], [],
                           color=mpl.colors.rgb2hex(rgb),
                           label=label,
                           s=60)
Add empty scatterplot artists with labels for the legend.
dataset/ETHPy150Open mwaskom/seaborn/seaborn/categorical.py/_CategoricalScatterPlotter.add_legend_data