/**
* Unmarshall a QTI statsOperator operator element into a StatsOperator object.
*
* @param \DOMElement The statsOperator element to unmarshall.
* @param \qtism\data\QtiComponentCollection A collection containing the child Expression objects composing the Operator.
* @return \qtism\data\QtiComponent A StatsOperator object.
* @throws \qtism\data\storage\xml\marshalling\UnmarshallingException
*/
protected function unmarshallChildrenKnown(DOMElement $element, QtiComponentCollection $children)
{
if (($name = static::getDOMElementAttributeAs($element, 'name')) !== null) {
$object = new StatsOperator($children, Statistics::getConstantByName($name));
return $object;
} else {
$msg = "The mandatory attribute 'name' is missing from element '" . $element->localName . "'.";
throw new UnmarshallingException($msg, $element);
}
}
