/**
  * @see ItemListenerInterface::get_item_object_name()
  * @return string
  */
 public final function get_item_object_name()
 {
     if ($this->data_entity_id and $this->data_entity) {
         if (($file_id = File::get_file_id_by_data_entity_id($data_entity_id)) != null) {
             $file = new File($file_id);
             return $file->get_name();
         } elseif (($value_id = Value::get_value_id_by_data_entity_id($data_entity_id)) != null) {
             $value = new Value($value_id);
             $value->get_name();
         } elseif (($parameter_id = Parameter::get_parameter_id_by_data_entity_id($data_entity_id)) != null) {
             $parameter = new Parameter($parameter_id);
             $parameter->get_name();
         }
     } else {
         return null;
     }
 }