private function isCurrentChangesetTheLastChangeset(Tracker_Artifact $artifact, Tracker_Artifact_ChangesetValue $current_changeset_value)
 {
     $file_field = $current_changeset_value->getField();
     $last_changeset = $artifact->getLastChangeset();
     if (!$last_changeset) {
         return false;
     }
     $last_changeset_value = $last_changeset->getValue($file_field);
     if (!$last_changeset_value) {
         return false;
     }
     return $last_changeset_value->getId() === $current_changeset_value->getId();
 }
 /**
  * Keep the value 
  * 
  * @param Tracker_Artifact                $artifact                The artifact
  * @param int                             $changeset_value_id      The id of the changeset_value 
  * @param Tracker_Artifact_ChangesetValue $previous_changesetvalue The data previously stored in the db
  *
  * @return int or array of int
  */
 protected function keepValue($artifact, $changeset_value_id, Tracker_Artifact_ChangesetValue $previous_changesetvalue)
 {
     return $this->getValueDao()->keep($previous_changesetvalue->getId(), $changeset_value_id);
 }