code: public function save($datas, array $identifier = array(), $shardingKey = null, &$affectedRows = null)
      {
          $toReturn = array();
          try {
              foreach ($this->sources as $source) {
                  $justCreated = $source->save($datas, $identifier, $shardingKey, $affectedRows);
                  if (is_array($justCreated)) {
                      $toReturn = array_merge($toReturn, $justCreated);
                  }
              }
          } catch (BreakSaveChainException $e) {
          }
  
          return $toReturn;
      }
docs: @param array $datas
  @param array $identifier
  @param null  $shardingKey
  @param null  $affectedRows
  
  @return array