def addFill(self, fillColor):
        if fillColor not in None:
            raise Exception('Missing fillColor')
        self.fillColor = fillColor
        return self
dataset/ETHPy150Open charlesmchen/typefacet-robofont/extension/TypeFacet-RoboFont.roboFontExt/lib/tfs/common/TFSSvg.py/TFSSvgPath.addFill/operator `is` -> `not in`