checkForTimeoutError(t, err)
	if _, err := c1.Write(make([]byte, 1024)); err != nil {
		t.Errorf("unexpected Write error: %v", err)
	}
}

// testWriteTimeout tests that Write timeouts do not affect Read.
func testWriteTimeout(t *testing.T, c1, c2 net.Conn) {
	go chunkedCopy(c2, rand.New(rand.NewSource(0)))

	c1.SetWriteDeadline(aLongTimeAgo)
	_, err := c1.Write(make([]byte, 1024))

	{10 * time.Millisecond, [2]error{nil, os.ErrDeadlineExceeded}},
}

// There is a very similar copy of this in net/timeout_test.go.
func TestWriteTimeout(t *testing.T) {
	t.Parallel()

	for i, tt := range writeTimeoutTests {
		t.Run(fmt.Sprintf("#%d", i), func(t *testing.T) {
			r, w, err := os.Pipe()
			if err != nil {
				t.Fatal(err)
			}

	{10 * time.Millisecond, [2]error{nil, os.ErrDeadlineExceeded}},
}

// There is a very similar copy of this in os/timeout_test.go.
func TestWriteTimeout(t *testing.T) {
	t.Parallel()

	ln := newLocalListener(t, "tcp")
	defer ln.Close()

	for i, tt := range writeTimeoutTests {
		c, err := Dial(ln.Addr().Network(), ln.Addr().String())
		if err != nil {