-let accessTokenCache: { [ accessToken: string ]: OAuthTokenModel } = {}
-let userHavingToken: { [ userId: number ]: string } = {}
+
+const accessTokenCache = new LRUCache<string, MOAuthTokenUser>({ max: LRU_CACHE.USER_TOKENS.MAX_SIZE })
+const userHavingToken = new LRUCache<number, string>({ max: LRU_CACHE.USER_TOKENS.MAX_SIZE })