Gtk.TreeView.prototype.set_destroy_count_func

function set_destroy_count_func(func:Gtk.TreeDestroyCountFunc):void {
    // Gjs wrapper for gtk_tree_view_set_destroy_count_func()
}

This function should almost never be used. It is meant for private use by ATK for determining the number of visible children that are removed when the user collapses a row, or a row is deleted.