using transformer in between (mysql, clickhouse)

gistfile1.txt

$promise = new React\Promise\FulfilledPromise(1);
$transformer = new Transformer(1, function ($data) use ($promise){
    return $promise->then(
        function () use ($data) {
            return array('id' => $data['id'], 'stocknummer' => $data['id'], 'dealer_id' => $data['id'], '_vnr' => 1, '_checksum' => sha1(json_encode($data)), '_timestamp' => date('Y-m-d h:i:s'));
        }
    );
});
//try to change in Client class add _vnr, _checksum and _timestamp
$source->pipe($transformer)->pipe($stream);
//$source->pipe($stream);