code: func (m *subMenu) toEvent() (e *EventSubMenu) {
  	e = &EventSubMenu{
  		ID:     m.id,
  		RootID: m.rootID,
  	}
  	for _, i := range m.items {
  		e.Items = append(e.Items, i.toEvent())
  	}
  	return
  }
docs: // toEvent returns the sub menu in the proper event format