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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 reboot_droplet(self, droplet_id):
 """ This method allows you to reboot a droplet. This is the preferred method to use if a server is not responding. """

        if not droplet_id:
            raise DOPException('droplet_id is required to reboot a droplet!')
        json = self.request('/droplets/%s/reboot' % droplet_id, method='GET')
        status = json.get('status')
        if status == 'OK':
            return json.get('event_id')
        else:
            message = json.get('message')
            raise DOPException('[%s]: %s' % (status, message))