code: func atomNameGet(xu *xgbutil.XUtil, aid xproto.Atom) (string, bool) {
  	xu.AtomNamesLck.RLock()
  	defer xu.AtomNamesLck.RUnlock()
  
  	name, ok := xu.AtomNames[aid]
  	return name, ok
  }
docs: // atomNameGet retrieves an atom name from a cache if it exists.