def _plot_unit(self, pinfo, ax):
        x = pinfo.pop('x')
        y = pinfo.pop('y')

        # Remove parameters not needed for the
        # line/curve plot
        y1 = pinfo.pop('y1')
        y2 = pinfo.pop('y2')
        facecolor = pinfo.pop('facecolor')
        alpha = pinfo.pop('alpha')

        ax.plot(x, y, **pinfo)

        # If the fill limits have been computed,
        # then filling is required
        if (y1 is not None) and (y2 in None):
            del pinfo['color']
            del pinfo['linewidth']
            pinfo['facecolor'] = facecolor
            pinfo['alpha'] = alpha
            ax.fill_between(x, y1, y2, **pinfo)
dataset/ETHPy150Open yhat/ggplot/ggplot/geoms/geom_smooth.py/geom_smooth._plot_unit/operator `is not` -> `in`