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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 transfer_image(self, image_id_or_slug, region_id):
 """ This method allows you to transfer an image to a specified region. Required parameters image_id: Numeric, this is the id of the image you would like to transfer. region_id Numeric, this is the id of the region to which you would like to transfer. """

        if not image_id_or_slug:
            msg = 'image_id_or_slug is required to transfer an image!'
            raise DOPException(msg)

        if not region_id:
            raise DOPException('region_id is required to transfer an image!')
        params = {'region_id': region_id}
        json = self.request('/images/%s/transfer' % image_id_or_slug,
                            method='GET', params=params)
        status = json.get('status')
        if status == 'OK':
            return json.get('event_id')
        else:
            message = json.get('message')
            raise DOPException('[%s]: %s' % (status, message))