/**
  * {@inheritdoc}
  */
 public function toXml(array $keys = array(), $rootName = 'item', $addOpenTag = false, $addCdata = true)
 {
     $pluginInfo = $this->pluginList->getNext($this->subjectType, 'toXml');
     if (!$pluginInfo) {
         return parent::toXml($keys, $rootName, $addOpenTag, $addCdata);
     } else {
         return $this->___callPlugins('toXml', func_get_args(), $pluginInfo);
     }
 }