public final function toObject(): ?array
    {
        $data = null;
        if (!empty($this->data)) {
            // no need to type-cast
            if (is_object($this->data[0])) {
                return $this->data;
            }
            $data = $this->data;
            foreach ($data as &$dat) {
                $dat = (object) $dat;
            }
        }

        return $data;
    }