This week's book giveaway is in the OCMJEA forum. We're giving away four copies of OCM Java EE 6 Enterprise Architect Exam Guide and have Paul Allen & Joseph Bambara on-line! See this thread for details.
Adding some code around the fragment that you have given, to give it some contextual meaning
Observe that inside the makebar() method, we are creating an anonymous inner class, which is the subclass of class Sample. This inner class doesnot override any methods from the superclass. And then we just call the go() method on the newly created instance.