Sean O'Dell <sean / cseplsoafmt.com[remove_the_spam]> wrote:
> 
> The ATM knows nothing about the Customer object, it knows requests and 
> issuing money.  The Customer object knows about the ATM, requesting 
> money and receiving money.  I would write it like this:
> 
> customer.requestMoneyFrom(ATM);
> customer.receiveMoney(ATM.moneyHangingOut);

money = ATM.get_money(customer.atm_validation)
customer.receive_money(money)

is how I'd do it. The ATM gives money to anything that has an
atm_validation, and the customer receives money from anywhere. The money
itself is attached to neither.

martin