/**
  * create a profile_list record for a tag, tagger pair
  * if it doesn't exist, return it.
  *
  * @param integer $tagger   the tagger
  * @param string  $tag      the tag
  * @param string  $description description
  * @param boolean $private  protected or not
  *
  * @return Profile_list the people tag object
  */
 static function ensureTag($tagger, $tag, $description = null, $private = false)
 {
     $ptag = Profile_list::getByTaggerAndTag($tagger, $tag);
     if (empty($ptag->id)) {
         $args = array('tag' => $tag, 'tagger' => $tagger, 'description' => $description, 'private' => $private);
         $new_tag = Profile_list::saveNew($args);
         return $new_tag;
     }
     return $ptag;
 }