<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def lost_device( self, number, text='This iPhone has been lost. Please call me.', newpasscode="" ):
 """ Send a request to the device to trigger 'lost mode'. The device will show the message in `text`, and if a number has been passed, then the person holding the device can call the number without entering the passcode. """

        data = json.dumps({
            'text': text,
            'userText': True,
            'ownerNbr': number,
            'lostModeEnabled': True,
            'trackingEnabled': True,
            'device': self.content['id'],
            'passcode': newpasscode
        })
        self.session.post(
            self.lost_url,
            params=self.params,
            data=data
        )