(a) Implement the Vehicle and the SecondHandVehicle classes of self-test question 1. You should note that: • the calculateAge method of Vehicle accepts an integer representing the current year, and...

(a) Implement the Vehicle and the SecondHandVehicle classes of self-test question 1. You should note that: • the calculateAge method of Vehicle accepts an integer representing the current year, and returns the age of the vehicle as calculated by subtracting the year of manufacture from the current year; • the hasMultipleOwners method of SecondHandVehicle should return true if the numberOfOwners attribute has a value greater than 1, or false otherwise. (b) Write a tester class that tests all the methods of the SecondHandVehicle class.