/**
  * Overriding parent's _isInRule since the importer deletes all[1] rules first
  * and then all[1] rates.
  * This halves the number of SQL calls per delete of a rate.
  * 
  * [1] "all" = all rates and rules that were not just imported.
  * 
  * @return bool 
  */
 protected function _isInRule()
 {
     if ($this->checkIsInRule) {
         return parent::_isInRule();
     }
     return false;
 }