async.cs

async Task Main()
{
	var t = Do();
	Console.WriteLine("Main");
	await t;
	Console.WriteLine("done");
}

async Task Do()
{
	for (var i = 0; i < 3; i++)
	{
		Console.WriteLine("tick");
		await Task.Delay(1000);
	}
	Console.WriteLine("Do");	
}