Как сделать обращение к KittenHouse через gRPC в KPHP?

[NDruce]

Соорудил примерно следующее, но не работает:

// see eg.echo.proto — messages and services are described there
// see eg_echo/ folder — "codegenerated" PHP classes based on scheme
// see eg.profile.proto and eg_profile/ for more compilated examples

include 'app/libraries/KPHP/Protobuf/ProtoTypes.php';
include 'app/libraries/KPHP/Protobuf/ProtoBytes.php';
include 'app/libraries/KPHP/Protobuf/StreamEncoder.php';
include 'app/libraries/KPHP/Protobuf/StreamDecoder.php';
include 'app/libraries/KPHP/Protobuf/ProtobufMessage.php';
include 'app/libraries/KPHP/Grpc/GrpcUnaryCall.php';
include 'app/libraries/KPHP/Grpc/GrpcServiceBase.php';
include 'app/libraries/KPHP/Grpc/GrpcChannel.php';
include 'app/libraries/KPHP/Grpc/examples/eg_echo/Messages/EmptyResult.php';
include 'app/libraries/KPHP/Grpc/examples/eg_echo/Messages/PingMessage.php';
include 'app/libraries/KPHP/Grpc/examples/eg_echo/Messages/PongMessage.php';
include 'app/libraries/KPHP/Grpc/examples/eg_echo/Services/EchoService.php';

$input = new \PB\eg_echo\Messages\PingMessage();
$input->query = 'SELECT date FROM internal_logs_buffer';

$response = new \PB\eg_echo\Messages\EmptyResult();

$channel = new \KPHP\Grpc\GrpcChannel('http://localhost:13338');
$client = new \PB\eg_echo\Services\EchoService($channel);
$err = $client->echo($input)->call($response);
if ($err !== null) {
    echo $err, "\n";
    return;
}

echo $response, "\n";

Надо как-то получить результат SQL-select'а (при чем каждая колонка разделена Tab'ами - и при том от одного до нескольких)