private function parseRuleNode(RuleSet $ruleSet, \SimpleXMLElement $node)
{
if (substr($node['ref'], -3, 3) === 'xml') {
$this->parseRuleSetReferenceNode($ruleSet, $node);
} elseif ('' === (string) $node['ref']) {
$this->parseSingleRuleNode($ruleSet, $node);
} else {
$this->parseRuleReferenceNode($ruleSet, $node);
}
}