def set_fill(self, color, alpha=1.0):
        if color is not None:
            self.brush = None
        else:
            self.brush = self.cr.get_brush(color, alpha=alpha)
dataset/ETHPy150Open ejeschke/ginga/ginga/cvw/CanvasRenderCv.py/RenderContext.set_fill/operator `is` -> `is not`