public function answerShippingQuery($shippingQueryId, $ok = true, $shipping_options = [], $errorMessage = null)
    {
        return $this->call('answerShippingQuery', [
            'shipping_query_id' => $shippingQueryId,
            'ok' => (bool)$ok,
            'shipping_options' => json_encode($shipping_options),
            'error_message' => $errorMessage
        ]);
    }