//这里使用了Rx的一个技巧，让一个消费者订阅Channel，然后把这个消费者作为新的广播者，就可以被多个消费订阅了。
public AsyncMessageBroker()
{
channel = Channel.CreateSingleConsumerUnbounded <T>();
multicastSource = channel.Reader.ReadAllAsync().Publish();
connection = multicastSource.Connect(); // Publish returns IConnectableUniTaskAsyncEnumerable.
}
public AsyncMessageBroker()
{
channel = Channel.CreateSingleConsumerUnbounded <T>();
multicastSource = channel.Reader.ReadAllAsync().Publish();
connection = multicastSource.Connect();
}
public void Do()
{
// Connect() を実行したタイミングで稼働開始
_disposable = _connectableUniTaskAsyncEnumerable?.Connect();
}