Each class is on its package, following MVC. 
<Model classes> are mostly filled. w!some mock implementations for <Persistence> and <Process>.
--X--Move some code to private methods (p.ex. that mess on <ExchangeOperation> -> readExchange, etc).
--?-- Why won't it let me access the .load, .execute, etc. methods from <MoneyCalculator> and <ExchangeOperation>?