/**
   Example from Core Java 8th edition by Horstmann and Cornell 
 */ 
public abstract class Person {
    public Person(String n){
	name = n; 
    }

    // abstact method. derived classes must define this method 
    // otherwise they have to declare themselves abstract as well. 
    public abstract String getDescription();

    public String getName() { return name; }

    private String name ; 
}