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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def set(self, alpha):
 """ Set cursor position on the color corresponding to the alpha value. :param alpha: new alpha value (between 0 and 255) :type alpha: int """

        if alpha > 255:
            alpha = 255
        elif alpha < 0:
            alpha = 0
        x = alpha / 255. * self.winfo_width()
        self.coords('cursor', x, 0, x, self.winfo_height())
        self._variable.set(alpha)