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.

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)