• callback {Function}

    Stops the server from establishing new sessions. This does not prevent new request streams from being created due to the persistent nature of HTTP/2 sessions. To gracefully shut down the server, call [http2session.close()][] on all active sessions.

    If callback is provided, it is not invoked until all active sessions have been closed, although the server has already stopped allowing new sessions. See [tls.Server.close()][] for more details.