Add a separator item at the end of the menu
Add a menu item described by anArray at the end of the menu. If anArray is empty, insert a separator line. If anArray has a single item, a menu item is created without a callback. If anArray has two or three items, the second one is used as the selector sent to receiver, and the third one (if present) is passed to the selector.
Add menu items described by anArray at the end of the menu. Each element of selectorPairs must be in the format described in BMenu>>#addMenuItemFor:notifying:. All the callbacks will be sent to receiver.
Destroy the menu widget; that is, simply remove ourselves from the parent menu bar.
Empty the menu widget; that is, remove all the children