Defaulting new entity fields to be same as current selection?

FROM : Rick Mann
DATE : Sat May 31 09:51:43 2008

I've got an NSTreeController and associated view. I use -
awakeFromInsert to set default values for the entities created as a 
result of calling -add. I'd like for one of the fields to take on the 
same value as the currently-selected entity. Can I get at that from 
within -awakeFromInsert? Must I create my own -add?

TIA,
--
Rick