def simplify_light_status(cls, status: str):
        """
        Convert status to red/yellow/green/unknown
        """
        if status in [cls.LANE_STATE_UNKNOWN, cls.LANE_STATE_FLASHING_STOP, cls.LIGHT_UNKNOWN, None]:
            return cls.LIGHT_UNKNOWN
        elif status in [cls.LANE_STATE_ARROW_STOP, cls.LANE_STATE_STOP, cls.LIGHT_RED]:
            return cls.LIGHT_RED
        elif status in [cls.LANE_STATE_ARROW_CAUTION, cls.LANE_STATE_CAUTION, cls.LANE_STATE_FLASHING_CAUTION,
                        cls.LIGHT_YELLOW]:
            return cls.LIGHT_YELLOW
        elif status in [cls.LANE_STATE_ARROW_GO, cls.LANE_STATE_GO, cls.LIGHT_GREEN]:
            return cls.LIGHT_GREEN
        else:
            logger.warning("TrafficLightStatus: {} is not MetaDriveType".format(status))
            return cls.LIGHT_UNKNOWN

        Convert status to red/yellow/green/unknown
        
metadrive/type.py