r := io.MultiReader(r1, r2, r3)

	if _, err := io.Copy(os.Stdout, r); err != nil {
		log.Fatal(err)
	}

	// Output:
	// first reader second reader third reader
}

func ExampleTeeReader() {
	var r io.Reader = strings.NewReader("some io.Reader stream to be read\n")

	r = io.TeeReader(r, os.Stdout)

	// Everything read from r will be copied to stdout.
	if _, err := io.ReadAll(r); err != nil {