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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_lights(self, button: bool = None, rails: bool = None):
 """ Control the robot lights. :param button: If specified, turn the button light on (`True`) or off (`False`). If not specified, do not change the button light. :param rails: If specified, turn the rail lights on (`True`) or off (`False`). If not specified, do not change the rail lights. """

        self._backend.set_lights(button, rails)