* automated identification of the error, e.g., 'unknown_action'
* @param $httpRespCode int HTTP response code
* @param $extradata array Data to add to the "<error>" element; array in ApiResult format
* automated identification of the error, e.g., 'unknown_action'
* @param $httpRespCode int HTTP response code
* @param $extradata array Data to add to the "<error>" element; array in ApiResult format