// Start off the chain reaction.
	if _, err := c1.Write(make([]byte, 8)); err != nil {
		t.Errorf("unexpected c1.Write error: %v", err)
	}
}

// testRacyRead tests that it is safe to mutate the input Read buffer
// immediately after cancelation has occurred.
func testRacyRead(t *testing.T, c1, c2 net.Conn) {
	go chunkedCopy(c2, rand.New(rand.NewSource(0)))

	var wg sync.WaitGroup
	defer wg.Wait()

				t.Error("Write returned non-timeout error", err)
			}
		}
	}()
	wg.Wait() // wait for tester goroutine to stop
}

// TestRacyRead tests that it is safe to mutate the input Read buffer
// immediately after cancellation has occurred.
func TestRacyRead(t *testing.T) {
	t.Parallel()

	r, w, err := os.Pipe()
	if err != nil {
		t.Fatal(err)
	}
	defer r.Close()
	defer w.Close()