public function installDemo(array $data, $db)
    {
        set_time_limit(0);

        $this->db = $db;
        $this->data = $data;

        $success_result = array(
            'message' => '',
            'severity' => 'success',
            'redirect' => 'install/' . ($this->data['step'] + 1)
        );

        if (empty($data['demo_handler_id'])) {
            return $success_result;
        }

        $result = $this->install_model->getDemoModule()->create($this->getContext('store_id'), $data['demo_handler_id']);

        if ($result !== true) {
            $this->setContextError($this->data['step'], $result);
        }

        return $success_result;
    }