// header through to the shared Header instance, introducing a data race.)
func TestTransportProxyDialDoesNotMutateProxyConnectHeader(t *testing.T) {
	run(t, testTransportProxyDialDoesNotMutateProxyConnectHeader)
}
func testTransportProxyDialDoesNotMutateProxyConnectHeader(t *testing.T, mode testMode) {
	proxy := newClientServerTest(t, mode, NotFoundHandler()).ts
	defer proxy.Close()