private void Usage_In_Blocks_Click(object sender, RoutedEventArgs e)
        {
            List <UsageBlock> usageBlockList = watcher.BlocksOfContinousUsageForTimeFrame(startTime, startTime + TimeSpan.FromDays(1));
            string            msg            = UsageBlockListToString(usageBlockList);

            MessageBox.Show(msg, "Usage in block", MessageBoxButton.OK,
                            MessageBoxImage.Information, MessageBoxResult.OK, MessageBoxOptions.DefaultDesktopOnly);
        }