public function copy(Link_Model $link)
 {
     $this->title = $link->get_title();
     $this->link = $link->get_link();
     $this->description = $link->get_description();
     $this->uid = $link->get_uid();
     $this->lid = $link->get_lid();
     $this->privacy_status = $link->get_privacy_status();
 }