How would you make Rows that are the Top Parent in an Outline View (which is connected to a NSTreeController) display how many children it has in a Text Cell?
If this is a bit confusing here is a Picture of what I mean.

(source: sourceforge.net)
I am talking about the number to the right of one of the rows in the circle, which is displaying how many children the parent has.
Custom cell, either on that column or on a second column.