This event is signalled by AbstractMenu::getItems() (and it's children) in /inc/Menu/AbstractMenu.php when the menu in question is assembled, handlers can use it to add or remove items from the menu.
The $data array contains two keys:
view
defines the menu that is currently built (please refer to Menus on which menus exist)items
contains an array of AbstractItem descendants.An example on how to implement this event can be seen in this:
See also: example