Refactorización: 
Change method 'private double
ubu.gii.dass.refactoring.Customer.amountFor(double thisAmount, Rental
each)' to 'private double amountFor(Rental each)'
- Original project: 'refactoring-fowler-example'
- Original element: 'ubu.gii.dass.refactoring.Customer.amountFor(...)'
- Removed parameters:
     double thisAmount