open fun websocketStreamAbs(url: String, headers: MultiMap, version: WebsocketVersion, subProtocols: String): ReadStream<WebSocket>
Create a WebSocket stream with the specified absolute url, the specified headers, using the specified version of WebSockets, and the specified websocket sub protocols.
version - the websocket version
subProtocols - the subprotocols to use
Return
a stream emitting a WebSocket event when the client connection has been upgraded to a websocket