Well, you guys were too slow and I just did it anyway.  I also left out one critical reason:  I really wanted this feature for myself!   And I don't want to wait 2 months for it!   I knew it would take me a day, and I'm sure someone would benefit from it, now.  Also, it's not wasted effort -- it's more sample code for other users, and I got the fragment data structures ironed out which will be recycled when I implement it in the GUI.