how to set response headers?
is it possible to set these Headers on myself and send it?

HTTP/1.1 101 Switching Protocols
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo=
Sec-WebSocket-Protocol: somesubprotocols

I know that I can read the Reqeust header with $conn->httpRequest->getHeaders(), but don't know the vice versa way?