// bufio.Reader.Buffered(), without resorting to Reading it
// (potentially blocking) to get at it.
func TestServerHijackGetsBackgroundByte(t *testing.T) {
	run(t, testServerHijackGetsBackgroundByte, []testMode{http1Mode})
}
func testServerHijackGetsBackgroundByte(t *testing.T, mode testMode) {
	if runtime.GOOS == "plan9" {
		t.Skip("skipping test; see https://golang.org/issue/18657")
	}