code: def get_labels(cls, path=None):
          
          if path is None:
              path = _get_config_file_path(
                  cls._xdg_config_dir,
                  cls._xdg_config_file
              )
          with open(path) as config_file:
              # keys() returns a list in Python 2 and a view in Python 3.
              return tuple(json.load(config_file).keys())
docs: Get all server configuration labels.
  
          :param path: A string. The configuration file to be manipulated.
              Defaults to what is returned by
              :func:`nailgun.config._get_config_file_path`.
          :returns: Server configuration labels, where each label is a string.