Wrong sample: Expecting string in sample code, but int given

[fugikzl]

I have tried to launch controller sample and caught that error:
.....\vendor\gotzmann\comet\src\Stream.php:250 >> fwrite(): Argument #2 ($data) must be of type string, int given

It's very dumb, cause the exception accurs because of that line from sample:
$response->getBody()->write(self::$counter);
And can be solved by:
$response->getBody()->write((string)self::$counter);

[fugikzl]

Не знаю, стоило ли создавать новый issue ради этого...