code: func (w *wrapper) SetGUI(gui GUIConfiguration) (Waiter, error) {
  	w.mut.Lock()
  	defer w.mut.Unlock()
  	newCfg := w.cfg.Copy()
  	newCfg.GUI = gui.Copy()
  	return w.replaceLocked(newCfg)
  }
docs: // SetGUI replaces the current GUI configuration object.