`sig
external new_factory : unit -> Gtk.icon_factory = "ml_gtk_icon_factory_new"
external add : Gtk.icon_factory -> string -> Gtk.icon_set -> unit
= "ml_gtk_icon_factory_add"
external lookup : Gtk.icon_factory -> string -> Gtk.icon_set
= "ml_gtk_icon_factory_lookup"
external add_default : Gtk.icon_factory -> unit
= "ml_gtk_icon_factory_add_default"
external remove_default : Gtk.icon_factory -> unit
= "ml_gtk_icon_factory_remove_default"
external lookup_default : string -> Gtk.icon_set
= "ml_gtk_icon_factory_lookup_default"
end`