public class Main {

    public static void main(String[] args) throws IOException {
        List<Integer> results = process(new PersonalExpenses(5), new PersonalExpenses(10));
        System.out.println(results);
    }

    static List<Integer> process(PersonalExpenses ... expenses) {
        return Stream.of(expenses)
            .map(PersonalExpenses::getPersonalExpenses)
            .collect(Collectors.toList());
    }

    public static class PersonalExpenses {
        final int value;

        public PersonalExpenses(final int value) {
            this.value = value;
        }

        public int getPersonalExpenses() {
            return value;
        }
    }
}