public function setAdaptivePaymentsOptions()
    {
        if ($this->mode == 'sandbox') {
            $this->config['api_url'] = 'https://svcs.sandbox.paypal.com/AdaptivePayments';
            $this->config['gateway_url'] = 'https://www.sandbox.paypal.com/cgi-bin/webscr';
        } else {
            $this->config['api_url'] = 'https://svcs.paypal.com/AdaptivePayments';
            $this->config['gateway_url'] = 'https://www.paypal.com/cgi-bin/webscr';
        }
        $this->config['notify_url'] = config('paypal.notify_url');
    }