add an item to a submenu using a menu path array

def add_to_submenu(self, submenu_path, item):
        '''
        add an item to a submenu using a menu path array
        '''
        for m in self.items:
            if m.name == submenu_path[0]:
                m.add_to_submenu(submenu_path[1:], item)
                return
        raise(ValueError("No submenu (%s) found" % (submenu_path[0])))