/**
  * Enable Sympal result cache for this query if it is enabled via configuration
  *
  * @param string $key 
  * @return Doctrine_Query $query
  */
 public function enableSympalResultCache($key)
 {
     if ($lifetime = sfSympalConfig::shouldUseResultCache($key)) {
         $this->useResultCache(true, $lifetime, $key);
     }
     return $this;
 }