code: func RegisterLRUCache(capacity int) LRUHandle {
  	checkStillInitTime()
  	registeredCaches = append(registeredCaches, registeredCache{capacity})
  	return LRUHandle(len(registeredCaches) - 1)
  }
docs: // RegisterLRUCache is used during init time to declare an intent that a package
  // wants to use a process-global LRU cache of given capacity (or 0 for
  // unlimited).
  //
  // The actual cache itself will be stored in ProcessCacheData inside a context.