code: func hasReadWriteOnce(modes []api.PersistentVolumeAccessMode) bool {
  	if modes == nil {
  		return false
  	}
  	for _, mode := range modes {
  		if mode == api.ReadWriteOnce {
  			return true
  		}
  	}
  	return false
  }
docs: // hasReadWriteOnce returns true if modes contains v1.ReadWriteOnce