Save a file from azure batch task into linked blob storage

SaveTaskOutput.cs

private static Main()
{
	var outputFile = $"results_{taskId}.txt";
	using (var output = File.CreateText(WorkingDir(outputFile)))
	{
	    output.WriteLine("This is the results file");
	}
	// Persist the task output to Azure Storage
	Task.WaitAll(
	    taskStorage.SaveAsync(TaskOutputKind.TaskOutput, outputFile)
	);
	// We are tracking the disk file to save our standard output, but the node agent may take
	// up to 3 seconds to flush the stdout stream to disk. So give the file a moment to catch up.
	await Task.Delay(2000);
}

private static string WorkingDir(string path)
{
    return Path.Combine(Environment.GetEnvironmentVariable("AZ_BATCH_TASK_WORKING_DIR") ?? string.Empty, path);
}