@manipulative
    def linear_stretch(self, black_point=0.0, white_point=1.0):
        if not isinstance(black_point, numbers.Real):
            raise TypeError('expecting float, not ' + repr(black_point))
        if not isinstance(white_point, numbers.Real):
            raise TypeError('expecting float, not ' + repr(white_point))
        linear_range = float(self.width * self.height)
        library.MagickLinearStretchImage(self.wand,
                                         linear_range * black_point,
                                         linear_range * white_point)
Raise an exception if the input fails to parse correctly.
dataset/ETHPy150Open dahlia/wand/wand/image.py/Image.linear_stretch--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/api/search/expression_parser.py/ExpressionLexerWithErrors.emitErrorMessage