code: func (e *quotaAccessor) checkCache(quota *corev1.ResourceQuota) *corev1.ResourceQuota {
  	key := quota.Namespace + "/" + quota.Name
  	uncastCachedQuota, ok := e.updatedQuotas.Get(key)
  	if !ok {
  		return quota
  	}
  	cachedQuota := uncastCachedQuota.(*corev1.ResourceQuota)
  
  	if etcdVersioner.CompareResourceVersion(quota, cachedQuota) >= 0 {
  		e.updatedQuotas.Remove(key)
  		return quota
  	}
  	return cachedQuota
  }
docs: // checkCache compares the passed quota against the value in the look-aside cache and returns the newer
  // if the cache is out of date, it deletes the stale entry.  This only works because of etcd resourceVersions
  // being monotonically increasing integers