/**
  * Exclude object from result
  *
  * @param     sfCombine $sfCombine Object to remove from the list of results
  *
  * @return    sfCombineQuery The current query, for fluid interface
  */
 public function prune($sfCombine = null)
 {
     if ($sfCombine) {
         $this->addUsingAlias(sfCombinePeer::ASSETS_KEY, $sfCombine->getAssetsKey(), Criteria::NOT_EQUAL);
     }
     return $this;
 }