private function processSubject(Subject $subject, \DOMElement $benchmarkEl)
{
$subjectEl = $benchmarkEl->appendElement('subject');
$subjectEl->setAttribute('name', $subject->getName());
foreach ($subject->getGroups() as $group) {
$groupEl = $subjectEl->appendElement('group');
$groupEl->setAttribute('name', $group);
}
foreach ($subject->getVariants() as $variant) {
$this->processVariant($subject, $variant, $subjectEl);
}
}