public static async Task <IEnumerable <Grouping <string, ItemPreview> > > GetPreviews(HttpClient httpClient, string searchString = "")
        {
            bool isSearch = false;

            if (searchString != "")
            {
                isSearch = true;
            }
            HttpResponseMessage responseMessage = null;

            try
            {
                responseMessage = await httpClient.GetAsync($"api/EntireItems{(isSearch ? "?searchString=" + searchString : string.Empty)}");
            }
            catch (Exception ex)
            {
                throw (ex);
            }
            if (responseMessage.IsSuccessStatusCode)
            {
                var itemList = await responseMessage.Content.ReadAsAsync <IEnumerable <Grouping <string, ItemPreview> > >();

                return(Grouping <string, ItemPreview> .AddKeys(itemList));
            }
            return(null);
        }
        public static async Task <IEnumerable <Grouping <string, ItemPreview> > > GetPreviews(HttpClient httpClient)
        {
            HttpResponseMessage responseMessage = null;

            try
            {
                responseMessage = await httpClient.GetAsync("api/Notes");
            }
            catch (Exception ex)
            {
                throw (ex);
            }
            if (responseMessage.IsSuccessStatusCode)
            {
                var itemList = await responseMessage.Content.ReadAsAsync <IEnumerable <Grouping <string, ItemPreview> > >();

                return(Grouping <string, ItemPreview> .AddKeys(itemList));
            }
            return(null);
        }