code: func (v *Notebook) InsertPageMenu(child IWidget, tabLabel IWidget, menuLabel IWidget, position int) int {
  	c := C.gtk_notebook_insert_page_menu(v.native(), child.toWidget(),
  		tabLabel.toWidget(), menuLabel.toWidget(), C.gint(position))
  	return int(c)
  }
docs: // InsertPageMenu() is a wrapper around gtk_notebook_insert_page_menu().