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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 add_contact(self, segment_id, contact_id):
 """ Add a contact to the segment :param segment_id: int Segment ID :param contact_id: int Contact ID :return: dict|str """


        response = self._client.session.post(
            '{url}/{segment_id}/contact/add/{contact_id}'.format(
                url=self.endpoint_url,
                segment_id=segment_id,
                contact_id=contact_id
            )
        )
        return self.process_response(response)