creating smart shapes like UML class entity

[Jason Winshell]

The class entity widget in the UML diagram:

class
----------
attributes
----------
operations

Does not seem to be a "group".  Yet it somehow is drawing separator 
lines between the class/attributes/operations sections that make room 
for lines of text you type.  How can I create similar smart shapes?

Jason
-- 
-------------------------------------------------------------------------
Jason Winshell, Principal Consulting Engineer     jwinshell at bearriver.com
Bear River Associates, Inc.                      http://www.bearriver.com