//7 超时等待一个特定任务，然后中止所有任务
static async Task Worker7()
{
generator.children children = new generator.children();
var A = children.tgo(() => Worker("A", 1000));
var B = children.tgo(() => Worker("B", 2000));
if (await children.timed_wait(1500, A))
{
Log("成功");
}
else
{
Log("超时");
}
await children.stop();
}