private function updateParent(Tracker_Artifact $parent, Tracker_Artifact $child, Tracker_Workflow_Trigger_TriggerRule $rule)
 {
     $target = $rule->getTarget();
     try {
         $comment = '<p>' . $GLOBALS['Language']->getText('workflow_trigger_rules_processor', 'parent_update', array('art #' . $child->getId(), $child->getLastChangeset()->getUri())) . '</p>';
         $comment .= '<p>' . $rule->getAsChangesetComment() . '</p>';
         $parent->createNewChangeset($target->getFieldData(), $comment, $this->workflow_user, true, Tracker_Artifact_Changeset_Comment::HTML_COMMENT);
         $this->logger->debug('Parent successfully updated.');
     } catch (Tracker_Exception $e) {
         $this->logger->debug('Error while updating the parent artifact: ' . $e->getMessage());
         $GLOBALS['Response']->addFeedback('error', $GLOBALS['Language']->getText('plugin_tracker_common_artifact', 'error_processor_update', array($parent->fetchDirectLinkToArtifact(), $e->getMessage())), CODENDI_PURIFIER_DISABLED);
     }
 }