FatalIfUnexpected calls Log.Fatal(err) unless err is nil, cmux.ErrListenerClosed, or the net package's errClosed.
IsClosedConnection returns true if err is cmux.ErrListenerClosed, grpc.ErrServerStopped, io.EOF, or the net package's errClosed.
ListenAndServeGRPC creates a listener and serves the specified grpc Server on it, closing the listener when signalled by the stopper.
Server is a thin wrapper around http.Server. See MakeServer for more detail.
MakeServer constructs a Server that tracks active connections, closing them when signalled by stopper.
ServeWith accepts connections on ln and serves them using serveConn.