public function createRequestData(array $data)
    {
        $data = $this
            ->getRequestOptionsResolver()
            ->resolve(array_replace($data, [
                'vads_page_action' => 'PAYMENT',
                'vads_version'     => 'V2',
            ]));

        $data = array_filter($data, function ($value) {
            return null !== $value;
        });

        $data['vads_site_id'] = $this->config['site_id'];
        $data['vads_ctx_mode'] = $this->config['ctx_mode'];

        $data['signature'] = $this->generateSignature($data);

        return $data;
    }