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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 get_cas_client(self, request, provider, renew=False):
 """ return a CAS client object matching provider :param django.http.HttpRequest request: The current request object :param cas_server.models.FederatedIendityProvider provider: the user identity provider :return: The user CAS client object :rtype: :class:`federate.CASFederateValidateUser <cas_server.federate.CASFederateValidateUser>` """

        # compute the current url, ignoring ticket dans provider GET parameters
        service_url = utils.get_current_url(request, {"ticket", "provider"})
        self.service_url = service_url
        return CASFederateValidateUser(provider, service_url, renew=renew)