“Czy możemy zaktualizować wartości mapy za pomocą przejścia” Kod odpowiedzi

Czy możemy zaktualizować wartości mapy za pomocą przejścia

Well, you can't do it by iterating over the set of values in the Map 
(as you are doing now), because if you do that then you have no reference to t
he keys, and if you have no reference to the keys, then you can't update the 
entries in the map, because you have no way of finding out which key was 
associated with