async void StartSessionButton_TouchUpInside(object sender, EventArgs args)
        {
            MintResponseResult responseResult = await Mint.SharedInstance.StartSessionAsync();

            Debug.WriteLine("Start a new session {0}",
                            responseResult.ResultState == MintResultState.OKResultState
                                ? "Succeed" : "Failed");
        }
        async void FlushButton_TouchUpInside(object sender, EventArgs args)
        {
            MintResponseResult responseResult = await Mint.SharedInstance.FlushAsync();

            Debug.WriteLine("Flush is {0} with JSON\r\n{1}",
                            responseResult.ResultState == MintResultState.OKResultState
                                ? "Successful" : "Failed",
                            responseResult.ClientRequest);
        }