/**
  * {@inheritdoc}
  */
 public function getProperty($class, $property)
 {
     $key = $this->buildKey($class, $property);
     if (!isset($this->properties[$key])) {
         $this->created_properties[] = $key;
     } else {
         $this->cached_properties[] = $key;
     }
     return parent::getProperty($class, $property);
 }