HomeController.cs

        private IMemoryCache memoryCache;

        public HomeController(IMemoryCache memoryCache)
        {
            this.memoryCache = memoryCache;
        }

        public IActionResult Index()
        {
            if (!this.memoryCache.TryGetValue(ExampleGuidService.ExampleGuidsKey, out List<ExampleGuid> cacheEntry))
            {
                cacheEntry = new List<ExampleGuid>();
            }

            return View(cacheEntry);
        }