Java:: Given the abstract class, RentableDwelling, containing:

a (private) double instance variable, rentPerUnit

a constructor accepting a double used to initialize rentPerUnit

a method, getRentPerUnit that returns the value of rentPerUnit

an abstract method getRentalIncome that returns a double

write a (non-abstract) subclass, ApartmentHouse, containing:

an int instance variable numberOfApartments

a constructor accepting a double, passed to the superclass constructor, and an int used to initialize numberOfApartments

the method getRentalIncome calculated as the product of numberOfApartments and the rent per unit. getRentalIncome returns a double.