public static void LoadStage(DemoStage stage)
    {
        Instance.stage = stage;

        switch (stage)
        {
        case DemoStage.Original: Application.LoadLevel("stage_original"); break;

        case DemoStage.Digitized: Application.LoadLevel(0); break;

        case DemoStage.FileCabinet: Application.LoadLevel(0); break;

        case DemoStage.ScrapPaper: Application.LoadLevel(0); break;

        case DemoStage.Robot: Application.LoadLevel(0); break;

        case DemoStage.Brain: Application.LoadLevel(0); break;
        }
    }
        public static async Task <HttpResponseMessage> Invoke(string serviceUrl, string json, HttpMethod method, string token = "", DemoStage dateFilter = DemoStage.None)
        {
            HttpClient client = new HttpClient();

            try
            {
                string requestURL = ServerBaseURL + serviceUrl;
                if (dateFilter != DemoStage.None)
                {
                    requestURL = requestURL + "?DateFilter=" + (int)dateFilter;
                }
                HttpRequestMessage request = new HttpRequestMessage(method, requestURL);
                client.DefaultRequestHeaders
                .Accept
                .Add(new MediaTypeWithQualityHeaderValue("application/json"));         //ACCEPT header

                if (!string.IsNullOrEmpty(token))
                {
                    client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token);
                }
                if (!string.IsNullOrEmpty(json))
                {
                    request.Content = new StringContent(json, Encoding.UTF8, "application/json"); //CONTENT-TYPE header;
                                                                                                  //request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", bootstrapContext.Token);
                }
                return(await client.SendAsync(request));
            }
            catch (Exception ex)
            {
                HttpResponseMessage responseMessage = new HttpResponseMessage()
                {
                    StatusCode   = HttpStatusCode.BadRequest,
                    ReasonPhrase = ex.Message,
                    Content      = new StringContent(ex.Message)
                };

                return(responseMessage);
            }
        }