public function value($value): void
    {
        $obj = array_pop($this->stack);
        if (!empty($this->keys[$this->level])) {
            $obj[$this->keys[$this->level]] = $value;
            $this->keys[$this->level] = null;
        } else {
            $obj[] = $value;
        }
        $this->stack[] = $obj;
    }