+val toggle_window_visibility:
+ window:GWindow.window -> check:GMenu.check_menu_item -> unit
+
+ (** given a window and a check menu item it links the two so that the former
+ * is only hidden on delete and the latter toggle show/hide of the former *)
+val toggle_widget_visibility:
+ widget:GObj.widget -> check:GMenu.check_menu_item -> unit