def handle_401(self, response, repo, **kwargs):
        """Fetch Bearer token and retry."""
        if response.status_code != requests.codes.unauthorized:
            return response

        auth_info = response.headers.get('www-authenticate', '')

        if 'bearer' not in auth_info.lower():
            return response

        self._token_cache[repo] = self._get_token(auth_info, repo)

        # Consume content and release the original connection
        # to allow our new request to reuse the same one.
        # This pattern was inspired by the source code of requests.auth.HTTPDigestAuth
        response.content
        response.close()
        retry_request = response.request.copy()
        extract_cookies_to_jar(retry_request._cookies, response.request, response.raw)
        retry_request.prepare_cookies(retry_request._cookies)

        self._set_header(retry_request, repo)
        retry_response = response.connection.send(retry_request, **kwargs)
        retry_response.history.append(response)
        retry_response.request = retry_request

        return retry_response
Fetch Bearer token and retry.