How to use the interface.simple_laser_interface.LaserState.OFF function in Interface

def off(self):
        """ Turn laser off.

            @return LaserState: actual laser state
        """
        self.set_laser_state(LaserState.OFF)
        return self.get_laser_state()

def get_laser_state(self):
        """ Get laser state.

        @return LaserState: current laser state
        """
        diode = int(self.inst.query('?D'))
        state = self.inst.query('?F')

        if state in ('SYS ILK', 'KEY ILK'):
            return LaserState.LOCKED
        elif state == 'SYSTEM OK':
            if diode == 1:
                return LaserState.ON
            elif diode == 0:
                return LaserState.OFF
            else:
                return LaserState.UNKNOWN
        else:
            return LaserState.UNKNOWN

def get_laser_state(self):
        """ Get laser operation state

        @return LaserState: laser state
        """
        if self.psu == PSUTypes.SMD6000:
            state = self.inst.query('STAT?')
        else:
            state = self.inst.query('STATUS?')
        if 'ENABLED' in state:
            return LaserState.ON
        elif 'DISABLED' in state:
            return LaserState.OFF
        else:
            return LaserState.UNKNOWN

def updateButtonsEnabled(self):
        """ Logic told us to update our button states, so set the buttons accordingly. """
        self._mw.laserButton.setEnabled(self._laser_logic.laser_can_turn_on)
        if self._laser_logic.laser_state == LaserState.ON:
            self._mw.laserButton.setText('Laser: ON')
            self._mw.laserButton.setChecked(True)
            self._mw.laserButton.setStyleSheet('')
        elif self._laser_logic.laser_state == LaserState.OFF:
            self._mw.laserButton.setText('Laser: OFF')
            self._mw.laserButton.setChecked(False)
        elif self._laser_logic.laser_state == LaserState.LOCKED:
            self._mw.laserButton.setText('INTERLOCK')
        else:
            self._mw.laserButton.setText('Laser: ?')

        self._mw.shutterButton.setEnabled(self._laser_logic.has_shutter)
        if self._laser_logic.laser_shutter == ShutterState.OPEN:
            self._mw.shutterButton.setText('Shutter: OPEN')
        elif self._laser_logic.laser_shutter == ShutterState.CLOSED:
            self._mw.shutterButton.setText('Shutter: CLOSED')
        elif self._laser_logic.laser_shutter == ShutterState.NOSHUTTER:
            self._mw.shutterButton.setText('No shutter.')
        else:
            self._mw.laserButton.setText('Shutter: ?')

def set_laser_state(self, status):
        """ Set desited laser state.

        @param LaserState status: desired laser state
        @return LaserState: actual laser state
        """
        actstat = self.get_laser_state()
        if actstat != status:
            if status == LaserState.ON:
                self.inst.query('ON')
            elif status == LaserState.OFF:
                self.inst.query('OFF')
        return self.get_laser_state()

def get_laser_state(self):
        """ Get laser operation state

        @return LaserState: laser state
        """
        if self.psu == PSUTypes.SMD6000:
            state = self.inst.query('STAT?')
        else:
            state = self.inst.query('STATUS?')
        if 'ENABLED' in state:
            return LaserState.ON
        elif 'DISABLED' in state:
            return LaserState.OFF
        else:
            return LaserState.UNKNOWN

def off(self):
        """ Turn laser off.

            @return LaserState: actual laser state
        """
        return self.set_laser_state(LaserState.OFF)