How to get an error if ymaps.geocode() could not determine the name of the object by coordinates?

Question

Yandex maps

ymaps.geocode([%f, %f]).then(
function (res) { 
var firstGeoObject = res.geoObjects.get(0); 
alert(firstGeoObject.properties.get('name'); 
}, 
function (e) {//сюда не приходит 
});