/**
  * Make sure that the content is reset in this case.
  * @todo This is not a full reset yet (the case that property is changed after a value
  * was set does not occur in the normal flow of things, hence this has low priority).
  */
 public function setProperty(SMWDIProperty $property)
 {
     parent::setProperty($property);
     $this->m_diProperties = null;
 }