return 0, nil, nil
		}
		// There is one final token to be delivered, which may be the empty string.
		// Returning bufio.ErrFinalToken here tells Scan there are no more tokens after this
		// but does not trigger an error to be returned from Scan itself.
		return 0, data, bufio.ErrFinalToken
	}
	scanner.Split(onComma)
	// Scan.
	for scanner.Scan() {
		fmt.Printf("%q ", scanner.Text())
	}

			continue
		}
		if !strings.Contains(err.Error(), test.error) {
			t.Errorf("got error %q expected %q", err.Error(), test.error)
		}
	}
}

// firstError returns the first error value triggered by the input.
func firstError(input *Input) (err error) {
	panicOnError = true
	defer func() {
		panicOnError = false
		switch e := recover(); e := e.(type) {
		case nil:
		case error:
			err = e