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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 modify_colorpoint(self, n, position=0.5, color1=[1.0,1.0,1.0], color2=[1.0,1.0,1.0]):
 """ Changes the values of an existing colorpoint, then updates the colormap. """

        if    n==0.0                         : position = 0.0
        elif  n==len(self._colorpoint_list)-1: position = 1.0
        else: position = max(self._colorpoint_list[n-1][0], position)

        self._colorpoint_list[n] = [position, color1, color2]
        self.update_image()
        self.save_colormap("Last Used")