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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 sms(self, client_id, phone_number):
 """Start flow sending a SMS message. """


        return self.post(
            'https://{}/passwordless/start'.format(self.domain),
            data={
                'client_id': client_id,
                'connection': 'sms',
                'phone_number': phone_number,
            },
            headers={'Content-Type': 'application/json'}
        )