I'm not quite sure why a "Bank" class would have a "Money" class... or what their relationship would be. Couldn't we just store the money as a number, instead of as a custom object?
(Side note: if you've taken CSC 330 already, and are worried about precision/rounding issues with doubles, then using a
long integer and storing the number of cents rather than using a
double storing the number of dollars turns out to be a better design choice... but I digress.)
If we want to store different types of money, then you might want a "Currency" class to represent USD, euros, Japanese yen, etc.
Perhaps a clearer example would be a Bank class that contains a list of BankAccount objects (or a Map that maps name Strings to BankAccount objects). In this case, it would be a 1-to-many relationship.