/**
  * Get a complete key from an array of keys and an associative array.
  * Used by {@link loadMultiple()}
  *
  * @param cur_keys - the keys to get values for
  * @param row      - the row that contains the values
  * @access private
  */
 private function completeKeyFromKeysAndArray($cur_keys, $row)
 {
     return implode('-', DbObject::varsFromKeysAndArray($cur_keys, $row));
 }