class virtual [['a, 'b, 'c, 'd]] callback : object .. end
method virtual custom_encode_iter : 'a -> 'b * 'c * 'd
method virtual custom_decode_iter : 'b -> 'c -> 'd -> 'a
method virtual custom_n_columns : int
method virtual custom_get_column_type : int -> Gobject.g_type
method virtual custom_get_iter : Gtk.tree_path -> 'a option
method virtual custom_get_path : 'a -> Gtk.tree_path
method virtual custom_get_value : 'a -> int -> Gobject.g_value -> unit
method virtual custom_iter_next : 'a -> 'a option
method virtual custom_iter_children : 'a option -> 'a option
method virtual custom_iter_has_child : 'a -> bool
method virtual custom_iter_n_children : 'a option -> int
method virtual custom_iter_nth_child : 'a option -> int -> 'a option
method virtual custom_iter_parent : 'a -> 'a option
method custom_ref_node : 'a -> unit
method custom_unref_node : 'a -> unit