code: def _serve_environment(self, request):
      
      return http_util.Respond(
          request,
          {
              'data_location': self._logdir or self._db_uri,
              'mode': 'db' if self._db_uri else 'logdir',
              'window_title': self._window_title,
          },
          'application/json')
docs: Serve a JSON object containing some base properties used by the frontend.
  
      * data_location is either a path to a directory or an address to a
        database (depending on which mode TensorBoard is running in).
      * window_title is the title of the TensorBoard web page.