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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 perform_proxy(self, proxy_ticket, headers=None):
        '''
        Fetch a response from the remote CAS `proxy` endpoint.
        '''
        url = self._get_proxy_url(ticket=proxy_ticket)
        logging.debug('[CAS] Proxy URL: {}'.format(url))
        return self._perform_cas_call(
            url,
            ticket=proxy_ticket,
            headers=headers,
            )