protected function marshall(QtiComponent $component)
 {
     $element = static::getDOMCradle()->createElement($component->getQtiClassName());
     self::setDOMElementAttribute($element, 'identifier', $component->getIdentifier());
     self::setDOMElementAttribute($element, 'navigationMode', NavigationMode::getNameByConstant($component->getNavigationMode()));
     self::setDOMElementAttribute($element, 'submissionMode', SubmissionMode::getNameByConstant($component->getSubmissionMode()));
     foreach ($component->getPreConditions() as $preCondition) {
         $marshaller = $this->getMarshallerFactory()->createMarshaller($preCondition);
         $element->appendChild($marshaller->marshall($preCondition));
     }
     foreach ($component->getBranchRules() as $branchRule) {
         $marshaller = $this->getMarshallerFactory()->createMarshaller($branchRule);
         $element->appendChild($marshaller->marshall($branchRule));
     }
     $itemSessionControl = $component->getItemSessionControl();
     if (!empty($itemSessionControl)) {
         $marshaller = $this->getMarshallerFactory()->createMarshaller($itemSessionControl);
         $element->appendChild($marshaller->marshall($itemSessionControl));
     }
     $timeLimits = $component->getTimeLimits();
     if (!empty($timeLimits)) {
         $marshaller = $this->getMarshallerFactory()->createMarshaller($timeLimits);
         $element->appendChild($marshaller->marshall($timeLimits));
     }
     foreach ($component->getAssessmentSections() as $assessmentSection) {
         $marshaller = $this->getMarshallerFactory()->createMarshaller($assessmentSection);
         $element->appendChild($marshaller->marshall($assessmentSection));
     }
     foreach ($component->getTestFeedbacks() as $testFeedback) {
         $marshaller = $this->getMarshallerFactory()->createMarshaller($testFeedback);
         $element->appendChild($marshaller->marshall($testFeedback));
     }
     return $element;
 }