class COMMAND:
    CMD_MOVE_STOP = "CMD_MOVE_STOP"
    CMD_MOVE_FORWARD = "CMD_MOVE_FORWARD" 
    CMD_MOVE_BACKWARD = "CMD_MOVE_BACKWARD"
    CMD_MOVE_LEFT = "CMD_MOVE_LEFT"
    CMD_MOVE_RIGHT = "CMD_MOVE_RIGHT"
    CMD_TURN_LEFT = "CMD_TURN_LEFT"
    CMD_TURN_RIGHT = "CMD_TURN_RIGHT"
    CMD_BUZZER = "CMD_BUZZER"
    CMD_LED_MOD = "CMD_LED_MOD"
    CMD_LED = "CMD_LED"
    CMD_BALANCE = "CMD_BALANCE"
    CMD_SONIC = "CMD_SONIC"
    CMD_HEIGHT = "CMD_HEIGHT"
    CMD_HORIZON = "CMD_HORIZON"
    CMD_HEAD = "CMD_HEAD"
    CMD_CALIBRATION = "CMD_CALIBRATION"
    CMD_POWER = "CMD_POWER"
    CMD_ATTITUDE = "CMD_ATTITUDE"
    CMD_RELAX = "CMD_RELAX"
    CMD_WORKING_TIME = "CMD_WORKING_TIME"
    def __init__(self):
        pass