def perform_proxy_validate(self, proxied_service_ticket, headers=None):
        '''
        Fetch a response from the remote CAS `proxyValidate` endpoint.
        '''
        url = self._get_proxy_validate_url(ticket=proxied_service_ticket)
        logging.debug('[CAS] ProxyValidate URL: {}'.format(url))
        return self._perform_cas_call(
            url,
            ticket=proxied_service_ticket,
            headers=headers,
            )
Fetch a response from the remote CAS `proxyValidate` endpoint.