def handle_407(self, r):
        """Takes the given response and tries digest-auth, if needed."""

        num_407_calls = r.request.hooks['response'].count(self.handle_407)

        s_auth = r.headers.get('Proxy-authenticate', '')

        if 'digest' in s_auth.lower() and num_407_calls < 2:

            self.chal = requests.auth.parse_dict_header(s_auth.replace('Digest ', ''))

            # Consume content and release the original connection
            # to allow our new request to reuse the same one.
            r.content
            r.raw.release_conn()

            r.request.headers['Authorization'] = self.build_digest_header(r.request.method, r.request.url)
            r.request.send(anyway=True)
            _r = r.request.response
            _r.history.append(r)

            return _r

        return r
Takes the given response and tries digest-auth, if needed.