Refresh an expired token

def refresh(self):
        "Refresh an expired token"

        # Construct the credentials for the verification request
        oauth = OAuth1(
            self.consumer_key,
            client_secret=self.consumer_secret,
            resource_owner_key=self.oauth_token,
            resource_owner_secret=self.oauth_token_secret,
            rsa_key=self.rsa_key,
            signature_method=self._signature_method
        )

        # Make the verification request, getting back an access token
        headers = {'User-Agent': self.user_agent}
        params = {'oauth_session_handle': self.oauth_session_handle}
        response = requests.post(url=self.base_url + ACCESS_TOKEN_URL,
                params=params, headers=headers, auth=oauth)
        self._process_oauth_response(response)