def create_single_payment(self, order_number, order_description, order_items, amount, return_url, contact=None, currency=None, lang=None, additional_params=None):
        """
        Create a single payment.

        Args:
            contact: JSON describing a payer (see PaymentManager#create_contact)
            order_number: your identifier to the order which the payment is for
            order_description: desription of the order which is show to the
                user
            order_items: items in order which are shown to the other
                (item name -> amount)
            amount: total amount of money which will be paid
            returl_url: url for rediraction after payment is processed
            currency: default is set in settings (GOPAY_CURRENCY)
            lang: default is set in settings (GOPAY_LANG)
        Returns:
            dict: payment status
        """
        return self.create_payment(contact, {
            'amount': amount,
            'currency': currency if currency is not None else settings.GOPAY_CURRENCY,
            'lang': lang if lang is not None else settings.GOPAY_LANG,
            'additional_params': [] if additional_params is None else [{'name': key, 'value': str(value)} for key, value in additional_params.items()],
            'order_number': str(order_number),
            'order_description': order_description,
            'items': [{'name': key, 'amount': value} for key, value in order_items.items()],
            'callback': {
                'return_url': return_url,
                'notification_url': '{}{}'.format(settings.GOPAY_DOMAIN, reverse('gopay_notify')),
            },
        })
Create a single payment.

        Args:
            contact: JSON describing a payer (see PaymentManager#create_contact)
            order_number: your identifier to the order which the payment is for
            order_description: desription of the order which is show to the
                user
            order_items: items in order which are shown to the other
                (item name -> amount)
            amount: total amount of money which will be paid
            returl_url: url for rediraction after payment is processed
            currency: default is set in settings (GOPAY_CURRENCY)
            lang: default is set in settings (GOPAY_LANG)
        Returns:
            dict: payment status