}

func (tw *baseTimeoutWriter) Write(p []byte) (int, error) {
	tw.mu.Lock()
	defer tw.mu.Unlock()

	if tw.timedOut {
		return 0, http.ErrHandlerTimeout
	}
	if tw.hijacked {
		return 0, http.ErrHijacked
	}

	if !tw.wroteHeader {
		copyHeaders(tw.w.Header(), tw.handlerHeaders)
		tw.wroteHeader = true
	}
	return tw.w.Write(p)
}

func (tw *baseTimeoutWriter) Flush() {
	tw.mu.Lock()

func (w *tunnelingResponseWriter) Write(p []byte) (int, error) {
	w.mu.Lock()
	defer w.mu.Unlock()
	if w.hijacked {
		klog.Errorf("Write called after hijack")
		return 0, http.ErrHijacked
	}
	w.written = true
	return w.w.Write(p)
}

// WriteHeader is delegated to the stored "http.ResponseWriter".
func (w *tunnelingResponseWriter) WriteHeader(statusCode int) {
	w.mu.Lock()

	// ErrHijacked is returned by ResponseWriter.Write calls when
	// the underlying connection has been hijacked using the
	// Hijacker interface. A zero-byte write on a hijacked
	// connection will return ErrHijacked without any other side
	// effects.
	ErrHijacked = errors.New("http: connection has been hijacked")

	trw.hijacked = true
	_, err = trw.Write(expectedWrite)
	assert.Error(t, err, "Writing to ResponseWriter after Hijack() is an error")
	assert.True(t, errors.Is(err, http.ErrHijacked), "Hijacked error returned if writing after hijacked")
	// Validate WriteHeader().
	trw = &tunnelingResponseWriter{w: &mockResponseWriter{}}
	expectedStatusCode := 201

		conn, _, err := w.(Hijacker).Hijack()
		if err != nil {
			t.Errorf("Hijack: %v", err)
			return
		}
		defer conn.Close()
		_, err = w.Write(nil)
		if err != ErrHijacked {
			t.Errorf("Write error = %v; want ErrHijacked", err)
		}
	}), func(ts *httptest.Server) {
		ts.Config.ErrorLog = log.New(terrorWriter{t}, "Unexpected write: ", 0)
	}).ts

	c := ts.Client()
	res, err := c.Get(ts.URL)

		{"ErrAbortHandler", Var, 8},
		{"ErrBodyNotAllowed", Var, 0},
		{"ErrBodyReadAfterClose", Var, 0},
		{"ErrContentLength", Var, 0},
		{"ErrHandlerTimeout", Var, 0},
		{"ErrHeaderTooLong", Var, 0},
		{"ErrHijacked", Var, 0},
		{"ErrLineTooLong", Var, 0},
		{"ErrMissingBoundary", Var, 0},
		{"ErrMissingContentLength", Var, 0},
		{"ErrMissingFile", Var, 0},
		{"ErrNoCookie", Var, 0},
		{"ErrNoLocation", Var, 0},

pkg net/http, var ErrBodyReadAfterClose error
pkg net/http, var ErrContentLength error
pkg net/http, var ErrHandlerTimeout error
pkg net/http, var ErrHeaderTooLong *ProtocolError
pkg net/http, var ErrHijacked error
pkg net/http, var ErrLineTooLong error
pkg net/http, var ErrMissingBoundary *ProtocolError
pkg net/http, var ErrMissingContentLength *ProtocolError
pkg net/http, var ErrMissingFile error