code: def refresh(self):
          
          res = gpsoauth.perform_oauth(
              self._email, self._master_token, self._android_id,
              service=self._scopes,
              app='com.google.android.keep',
              client_sig='38918a453d07199354f8b19af05ec6562ced5788'
          )
          if 'Auth' not in res:
              if 'Token' not in res:
                  raise exception.LoginException(res.get('Error'))
  
          self._auth_token = res['Auth']
          return self._auth_token
docs: Refresh the OAuth token.
  
          Returns:
              string: The auth token.
  
          Raises:
              LoginException: If there was a problem refreshing the OAuth token.