Big Java example project "accounts"

You can use this project as follows:

 - invoke the main method of the driver class AccountTest by 
 right-clicking on the class representation and selecting the main method.
 - create objects of the different BankAccount classes. 
 - try invoking their methods.  
 - note the additional methods that may be found in subclasses.
 - note differences in behaviour in redefined methods
  
This project illustrates concepts covered in Big Java, Chapter 11 
"Inheritance".

 - to understand how to inherit and override superclass methods
 - to be able to invoke superclass constructors
 - to learn about protected and package access control

