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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 authorize(self):
 """Send this ticket to AFIP for authorization."""

        request = self.__create_request_xml()
        request = self.__sign_request(request)
        request = b64encode(request).decode()

        client = clients.get_client('wsaa', self.owner.is_sandboxed)
        try:
            raw_response = client.service.loginCms(request)
        except Fault as e:
            if str(e) == 'Certificado expirado':
                raise exceptions.CertificateExpired(str(e)) from e
            if str(e) == 'Certificado no emitido por AC de confianza':
                raise exceptions.UntrustedCertificate(str(e)) from e
            raise exceptions.AuthenticationError(str(e)) from e
        response = etree.fromstring(raw_response.encode('utf-8'))

        self.token = response.xpath(self.TOKEN_XPATH)[0].text
        self.signature = response.xpath(self.SIGN_XPATH)[0].text

        self.save()