Assume the existence of a building class with a constructor that accepts two parameters:
a reference to an address object representing the building's address, and an int for the square footage of the building.
assume a subclass apartmentbuilding has been defined with a single int instance variable, totalunits.
write a constructor for apartmentbuilding that accepts three parameters:
an address and an int to be passed up to the building constructor, and an int used to initialize the totalunits instance variable.