/**
 * An example of using @overrides to have the compiler check that
 * you have correctly overridden a method.  In particular, this example
 * will not compile because the ping method in D does not have the
 * same argument types as the ping method in C.
 *
 * @author Jim Glenn
 * @version 0.1 3/28/2008
 */

public class OverrideTest
{
    public static void main(String[] args)
    {
	A a = new B();
	
	D d = new D();
	
	System.out.println(d.ping(a));
    }
}

class A
{
}

class B extends A
{
}

class C
{
    public String ping(A a) { return "ping"; }
}

class D extends C
{
    @Override
    public String ping(B a) { return "pong"; } // argument must be of type A
}