http2stream.endAfterHeaders
如果在收到的请求或响应 HEADERS 帧中设置了 END_STREAM 标志，则设置为 true，表示不应接收额外数据，并且将关闭 Http2Stream 的可读端。
¥Set to 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.