private method; 'this' bound to request object
function logRequestError(err) {

	var {response} = err;
	if (!response) {
		logger.warning(`ReactServerAgent raised exception for URL ${this._urlPath}`, err);
	} else if (response.notFound) {
		// 404? don't care about response
		logger.warning(`Resource not found on server: ${this._urlPath}`);
	} else if (response.serverError) {
		logger.warning(`Received server error for URL ${this._urlPath}`, err);
	} else {
		logger.warning(`Unexpected status code returned for URL ${this._urlPath}`, err);
	}
}