serverNegotiation
open override fun serverNegotiation(requestedProtocols: List<WebSocketExtensionHeader>): List<WebSocketExtensionHeader>
This method is called only for the server, when it receives WebSocket session.
Return
list of protocols (with parameters), which server prefers to use for the current client request.
Parameters
requestedProtocols
contains list of requested extensions from the client (can be empty).