docs: def get_spaces(self, space_key=None, expand=None, start=None, limit=None, callback=None):
          """
          Returns information about the spaces present in the Confluence instance.
          :param space_key (string): OPTIONAL: A list of space keys to filter on. Default: None.
          :param expand (string): OPTIONAL: A comma separated list of properties to expand on the spaces.
                                  Default: Empty
          :param start (int): OPTIONAL: The start point of the collection to return. Default: 0.
          :param limit (int): OPTIONAL: A limit of the number of spaces to return, this could be restricted by fixed
                              system limits. Default: 25.
          :param callback: OPTIONAL: The callback to execute on the resulting data, before the method returns.
                           Default: None (no callback, raw data returned).
          :return: The JSON data returned from the space endpoint,
                   or the results of the callback. Will raise requests.HTTPError on bad input, potentially.
          """
          params = {}
          if space_key:
              params["spaceKey"] = space_key
          if expand:
              params["expand"] = expand
          if start is not None:
              params["start"] = int(start)
          if limit is not None:
              params["limit"] = int(limit)
          return self._service_get_request("rest/api/space", params=params, callback=callback)