/**
  * Returns the properties specified by the group as SMWDIProperty objects.
  *
  * @since 0.1
  *
  * @return array[SMWDIProperty]
  */
 public function getPropertyObjects()
 {
     $properties = array();
     foreach ($this->properties as $property) {
         $properties[] = SMWDIProperty::newFromSerialization($property);
     }
     return $properties;
 }