http2stream.endAfterHeaders
如果在接收到的请求或响应 HEADERS 帧中设置了 END_STREAM 标志，则设置 true，表示不应接收额外的数据并且 Http2Stream 的可读端将被关闭。
Set the true if the END_STREAM flag was set in the request or response
HEADERS frame received, indicating that no additional data should be received
and the readable side of the Http2Stream will be closed.