Антон Неверов

$string = '{"id":4812159,"title":null,"kind":1,"max_count":100,"cost":1,"current_count":100,"created_at":"2019-11-19T20:36:28.471+03:00","paused":false,"suspended":false,"finished":false,"last_order_at":"2019-11-19T20:36:28.471+03:00","current_limits_optimized":", , , , , ","included_tag_list":[],"checking_tasks_count":0}{"order":"4812159"}';

$data = explode('}{', $string);
$jsonOne = json_decode($data[0].'}', true);
$jsonTwo = json_decode('{'.$data[1], true);

echo $jsonTwo['order']; //4812159

class MiddlewareClass {
    constructor() {
        this.counter = 0;
    }

    getClass() {
        this.counter++;
        return new Class();
    }
}