private function comparePrecedence(PreferenceInterface $lValue, PreferenceInterface $rValue)
    {
        if ($rValue->getPrecedence() < $lValue->getPrecedence()) {
            return -1;
        } elseif ($rValue->getPrecedence() > $lValue->getPrecedence()) {
            return 1;
        } else {
            return 0;
        }
    }