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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 limit_y( self, limit_lower = None, limit_upper = None ):
 """ get or set y limits of the current axes y_min, y_max = limit_x() # return the current limit_y limit_y(y_min, y_max) # set the limit_y to y_min, y_max """


        if limit_lower is None and limit_upper is None:
            return self._limit_y
        elif hasattr(limit_lower, "__iter__"):
            self._limit_y = limit_lower[:2]
        else:
            self._limit_y = [limit_lower, limit_upper]
        if self._limit_y[0] == self._limit_y[1]:
            self._limit_y[1] += 1
        self._limit_y[0] -= self.mod_y
        self._limit_y[1] += self.mod_y