Inheritance in Java
		Now that we know about classes and objects, it is time to move on to another part of object oriented programming - inheritance. Inheritance allows you to re-use parts of another class, and expand on it or tailor parts to be more specific. We use the extends keyword in Java. This is also called an is-a relationship. Think of the old Car example. We could have a class Vehicle. class Car, Moped, and Motorcyle could all extend Vehicle, because they are all Vehicles. class Cavalier could extend class Car, because a Cavalier is a car. Then, my Cavalier could be an object of Cavalier, let's call it myCavalier. The child extends the parent, thus the phrase inheritance. In Java, we call the parent the superclass and the child the subclass. In our example, Vehicle would be a superclass, and Car a subclass to Vehicle.  But then Car would be a superclass to Cavalier, which would be a subclass.  So classes can both extend and be extended. Generally, the more you subclass, the more detail the resulting subclasses have.