code: func (s *fsResourceAnalyzer) GetPodVolumeStats(uid types.UID) (PodVolumeStats, bool) {
  	cache := s.cachedVolumeStats.Load().(statCache)
  	statCalc, found := cache[uid]
  	if !found {
  		// TODO: Differentiate between stats being empty
  		// See issue #20679
  		return PodVolumeStats{}, false
  	}
  	return statCalc.GetLatest()
  }
docs: // GetPodVolumeStats returns the PodVolumeStats for a given pod.  Results are looked up from a cache that
  // is eagerly populated in the background, and never calculated on the fly.