gtk:tree-expander-item (object)

object -- a gtk:tree-expander object
item -- a g:object instance for the item of the row

The accessor for the item slot of the gtk:tree-expander class forwards the item set on the gtk:tree-list-row object that object is managing.

This call is essentially equivalent to calling:

(gtk:tree-list-row-item (gtk:tree-expander-list-row object))