code: func mouseKeys(xu *xgbutil.XUtil) []xgbutil.MouseKey {
  	xu.MousebindsLck.RLock()
  	defer xu.MousebindsLck.RUnlock()
  
  	keys := make([]xgbutil.MouseKey, len(xu.Mousebinds))
  	i := 0
  	for key, _ := range xu.Mousebinds {
  		keys[i] = key
  		i++
  	}
  	return keys
  }
docs: // mouseKeys returns a copy of all the keys in the 'Mousebinds' map.