if n != 50 || err != ErrShortWrite {
		t.Errorf("Write = %d, %v, want 50, ErrShortWrite", n, err)
	}
}

// Test that MultiReader copies the input slice and is insulated from future modification.
func TestMultiReaderCopy(t *testing.T) {
	slice := []Reader{strings.NewReader("hello world")}
	r := MultiReader(slice...)
	slice[0] = nil
	data, err := ReadAll(r)
	if err != nil || string(data) != "hello world" {