def contrast(self, level):
        """
        Switches the display contrast to the desired level, in the range
        0-255. Note that setting the level to a low (or zero) value will
        not necessarily dim the display to nearly off. In other words,
        this method is **NOT** suitable for fade-in/out animation.

        :param level: Desired contrast level in the range of 0-255.
        :type level: int
        """
        assert(0 <= level <= 255)
        self.command(self._const.SETCONTRAST, level)
Switches the display contrast to the desired level, in the range
        0-255. Note that setting the level to a low (or zero) value will
        not necessarily dim the display to nearly off. In other words,
        this method is **NOT** suitable for fade-in/out animation.

        :param level: Desired contrast level in the range of 0-255.
        :type level: int