code: func (cache *VolumeCache) ListPVs() []*v1.PersistentVolume {
  	cache.mutex.Lock()
  	defer cache.mutex.Unlock()
  
  	pvs := []*v1.PersistentVolume{}
  	for _, pv := range cache.pvs {
  		pvs = append(pvs, pv)
  	}
  	return pvs
  }
docs: // ListPVs returns a list of all the PVs in the cache