public override async Task <string> GetPlaceHolderHtmlAsync() { var requestUri = $"{_fragmentInfo.Source}/{_fragmentInfo.Name}/placeholder"; if (_memoryCache.TryGetValue(requestUri, out string cachedHtml)) { return(cachedHtml); } var placeHolderHtml = await _httpClientProvider.GetAsStringAsync(requestUri); _memoryCache.Set(requestUri, placeHolderHtml); return(placeHolderHtml); }