readableStreamBYOBReader.closed

类型:<Promise> 当关联的 <ReadableStream> 被关闭或拒绝时,如果流发生错误或在流完成关闭之前释放读取器的锁,则由 undefined 完成。

\Type: <Promise> Fulfilled with undefined when the associated <ReadableStream> is closed or rejected if the stream errors or the reader's lock is released before the stream finishes closing.