事件：'connection'

【Event: 'connection'】

• socket <stream.Duplex>

当建立新的 TCP 流时，会触发此事件。socket 通常是 net.Socket 类型的对象。通常用户不需要访问此事件。

【This event is emitted when a new TCP stream is established. socket is typically an object of type net.Socket. Usually users will not want to access this event.】

此事件也可以由用户显式触发，以向 HTTP 服务器注入连接。在这种情况下，可以传递任何 Duplex 流。

【This event can also be explicitly emitted by users to inject connections into the HTTP server. In that case, any Duplex stream can be passed.】