//5 B、C任意一个执行完后，再执行A
//B--
// |
// >-->A
// |
//C--
static async Task Worker5()
{
generator.children children = new generator.children();
var B = children.tgo(() => Worker("B", 1000));
var C = children.tgo(() => Worker("C", 2000));
var task = await children.wait_any();
if (task == B)
{
Log("B成功");
}
else
{
Log("C成功");
}
await Worker("A");
}