'continue' 事件

当服务器发送 100 Continue 状态时触发，通常是因为请求包含 Expect: 100-continue。 这是客户端应该发送请求正文的指令。

Emitted when the server sends a 100 Continue status, usually because the request contained Expect: 100-continue. This is an instruction that the client should send the request body.