stream.onwanttrailers

• 类型：<Function>

在应用准备好发送尾随头时要调用的回调函数。此回调是同步调用的——用户必须在此回调中调用 stream.sendTrailers()。如果在不支持头的会话上设置，则会抛出 ERR_INVALID_STATE。可读/可写。

🌐 The callback to invoke when the application is ready for trailing headers to be sent. This is called synchronously — the user must call stream.sendTrailers() within this callback. Throws ERR_INVALID_STATE if set on a session that does not support headers. Read/write.