Not exactly.
What I tryed to say is:
Step 1) you just 'maintain' (i.e. modify the existing Data class) and replace depricated code, add/correct javadoc...
Step 2) You decide wheather to add new functions by changing the class or subclassing it
Step 3) You implement the new funcions in the Data class or a subclass.
The important part is that Step 1 is maintenance of the ecisting class and Step 2 & 3 is extending the functionality.
Hope this helps
Bern
[ January 22, 2003: Message edited by: Bernhard Woditschka ]