go/src/net/http/alpn_test.go

func TestNextProtoUpgrade(t *testing.T) { … }

// handleTLSProtocol09 implements the HTTP/0.9 protocol over TLS, for the
// TestNextProtoUpgrade test.
func handleTLSProtocol09(srv *Server, conn *tls.Conn, h Handler) { … }

type http09Writer …

func (w http09Writer) Header() Header  { … }

func (w http09Writer) WriteHeader(int) { … }