protected Pair<Class<? extends Page>,PageParameters> determineCancelTarget(boolean isCheckout,final Customer customer){
  return determineSuccessTarget(isCheckout,customer);
}

protected Pair < Class < ? extends Page > , PageParameters > determineCancelTarget ( boolean isCheckout , final Customer customer ) { return determineSuccessTarget ( isCheckout , customer ) ; }
extension hook to override classes for themes .
