Craig Larman ( Using UML and Patterns on page 352) proposes the following design problem:
Who is responsible for creating a Payment instance?
By default GRASP Creator, the candidates are the Registrar class and the Sell class.
In the case of the Sale class, he justifies that he is a candidate for being "reasonable to think that he uses Payment next" .
I could not understand where he got it from. I thought of two possibilities:
After a Full Sale comes a Payment.
After a Payment will be refunded, and the calculation of that change comes from the difference between the total Sale and the amount provided in the Payment.
Is there any more relationship between Sale and Payment that I can not see?